ALBERT

Beschreibung: Marine inundation hazards in French Polynesia are various and unevenly distributed in the territory; they are strongly related to the physiography (topography, bathymetry, coral reef development) of these oceanic islands. Cyclones and tsunamis appear as predominant processes in the definition of coastal flooding risks for Polynesian people. This study examines the geomorphic impacts of Tropical Cyclone Oli, which struck the western part of French Polynesia in February 2010. Submarine reef erosion is quantified through coral colony degree of destruction and massive coral colony displacement. Sediment transport and beach retreat are quantified, and flow velocities at the coastline are estimated through boulder analysis. Erosion and resilience of a sandy bank (cay) at the reef margin is also considered on Tubuai Island through satellite image analysis and GPS field survey. Outer-reef slope angle appears as a major control factor for coral destruction, with vertical submarine cliffs relatively shielded compared to gentle slopes. Submarine boulder measurements provide valuable estimates of flow velocity profile with depth. Beachrock slab measurements also provide estimates of flow velocities at the reef–beach junction. Combining these different geomorphic markers might be a way to apprehend the flow velocity variation when the cyclone waves cross the coral reef.

Beschreibung: In the past few years, large earthquakes and torrential rain hit southern Taiwan and induced severe submarine hazards off the SW coast. Marine sediments (turbidites) provide valuable records with which to study and understand the formation of these submarine geo-hazards. The Pingtung Earthquake (two major events (ML=7.0) plus many aftershocks), on 26 December 2006, triggered turbidity currents that severed submarine cables in the Fangliao and Gaoping submarine canyons. This caused significant economic loss. In addition to earthquake activity, typhoons and torrential rains that induced flooding are also important mechanisms responsible for the formation of turbidites. On 8–9 August 2009 Typhoon Morakot brought heavy rains to southern Taiwan, causing serious landslides and flooding on land. The typhoon also caused submarine cable breaks in the Gaoping Canyon. All such events are likely to be recorded in the marine sediments of the canyon system, and by analysing these records we may be able to reconstruct the history of past earthquakes and floods in the region. Chirp sonar profiles, in conjunction with core analysis, including X-ray radiographs, grain size and 210Pb analysis, are used to identify the sources, transport and deposition of the turbidites (or hyperpycnite) and to reconstruct the history of earthquakes and flooding in the study area. Results indicate that these submarine hazards are not only related to earthquake and floods but that the unique geological and hydrological setting also plays an important role in the initiation of these submarine geo-hazards.

Beschreibung: The 2004 Indian Ocean tsunami deposited an extensive sandsheet on the coastal plain of SE India. At particular sites, the sedimentary bedding in the sandsheet provides evidence of variable energy conditions and flow during inundation of the coast. Trenching of the deposits at sites where only unidirectional flow was observed allowed the investigation of changes in hydrodynamics recorded in bedding structures without the added complexity of return flows and reworking. A high-velocity initial surge is recorded as upper flow regime (UFR) plane bedding. Following the initial high flow a period of falling flow velocity and quiescence occurs where sediments settle out of suspension, often resulting in a reverse graded bed that transitions to a graded (fining-up) bed. As water levels begin to decline after maximum inundation sheet flow caused the formation of inversely graded (coarsening-up) beds or a return to UFR conditions. At one site the final stages of tsunami inundation is recorded as small channels that have an erosional base and are filled with graded sediments that exhibit complex patterns of sedimentation. Pits excavated in areas of unidirectional flow allow the development of a sedimentary model for tsunami sediment dynamics across flat topography under unidirectional flow conditions.

Beschreibung: This paper examines communication methods used to inform the vulnerable community of Hilo, Hawaii of the impending tsunamis that struck in 1946 and 1960. These tsunamis caused tragic loss of life and enormous economic damage in Hilo and along the shores of the Hawaiian Island chain. Over 12 h notice of a possible large tsunami was given in 1960 and the siren warning system sounded more than 4 h prior to the event. The government agencies knew there was a tsunami alert and the media were broadcasting warnings. However, the 1960 tsunami took the lives of 61 people in Hilo only 14 years after 96 people were killed during the 1946 event. In order to discover why so many people perished, government agency logs recorded during the 1960 tsunami were examined and personal accounts from survivors of both the 1946 and 1960 tsunamis were analysed. Contributing to the tragic loss of life was a lack of communication between government agencies in addition to media inaccuracies and a public that was not educated in tsunami safety. Effective tsunami mitigation can only be accomplished through continual tsunami awareness education for the public, media and emergency personnel, and with accurate and timely tsunami warnings.

Beschreibung: Geomorphological features associated with groundwater discharge zones can affect ground conditions so greatly that they determine the outcomes of battles. Two cases in point are found in Scottish history: (i) despite outnumbering their English foes, the Scots lost the Battle of Flodden Field (9 September 1513), largely due to failing to identify the presence of marshy ground associated with an area of groundwater discharge; (ii) on 21 September 1745, the Jacobites defeated the Hanoverian army at Prestonpans by finding a way around marshland corresponding to a regional groundwater discharge zone, upon which the Hanoverian commander had been relying as a natural defensive feature. Analysis of both battlefields drawing upon present-day understanding of local stratigraphy and hydrogeological conditions allows identification of the specific groundwater discharge patterns that largely determined the outcomes of these two emblematic battles. At Flodden, the proximal source of groundwater discharge is Quaternary outwash gravels, distally fed from sedimentary strata (Cementstones) of lowermost Dinantian age. In the case of Prestonpans, the groundwater emerges from particularly arenaceous coal-bearing strata of Namurian age. Both case studies suggest that military commanders selecting advantageous terrain could benefit from consulting hydrogeologists who are familiar with the intricacies of groundwater geomorphology.

Beschreibung: To drill boreholes for water supply, the Royal Engineers raised ten ‘Boring Sections’ between September 1939 and May 1943, eight in the UK, two in Egypt. While supporting campaigns in World War II, two deployed briefly to France, seven served widely within the Middle East (one of these in Iraq and Iran and later Malta, the others mostly operating from Egypt), one deployed to Algeria/Tunisia, four to Sicily and/or Italy (one of these onward to Greece), two deployed to support the D-Day Allied landings in Normandy and the subsequent advance via Belgium to Germany, and three served long-term in the UK. Greatest use was by Middle East Command, which at its peak had about 35 officers, 750 men and 40 drilling rigs assigned to water supply, and whose boreholes attained a cumulative length of some 40 km. The British Army used geology to help guide emplacement of boreholes in all these regions. Innovations included groundwater prospect maps at scales of 1:50 000 and 1:250 000, to help planning for the Allied invasion of Normandy and the subsequent campaign in NW Europe. Geology also helped guide groundwater abstraction by Indian Engineers in the Far East, and British/South African troops in East Africa.

Beschreibung: In this timely volume, geoscientists from both industry and academia present a contemporary view of salt at a global scale. The studies examine the influence of salt on synkinematic sedimentation, its role in basin evolution and tectonics, and ultimately in hydrocarbon prospectivity. Recent improvements in seismic reflection, acquisition and processing techniques have led to significant advances in the understanding of salt and sediment interactions, both along the flanks of vertical or overturned salt margins, and in subsalt plays such as offshore Brazil. The book is broadly separated into five major themes covering a variety of geographical and process-linked topics. These are: halokinetic sequence stratigraphy, salt in passive margin settings, Central European salt basins, deformation within and adjacent to salt, and salt in contractional settings and salt glaciers.

Beschreibung: Large rock inclusions are embedded in many salt bodies and these respond to the movements of the salt in a variety of ways including displacement, folding and fracturing. One mode of salt tectonics is downbuilding, whereby the top of a developing diapir remains in the same vertical position while the surrounding overburden sediments subside. We investigate how the differential displacement of the top salt surface caused by downbuilding induces ductile salt flow and the associated deformation of brittle stringers by an iterative procedure to detect and simulate conditions for the onset of localization of deformation in a finite element model, in combination with adaptive remeshing. The model set-up is constrained by observations from the South Oman Salt Basin, where large carbonate bodies encased in salt form substantial hydrocarbon plays. The model shows that, depending on the displacement of the top salt, the stringers can break very soon after the onset of salt tectonics and can deform in different ways. If extension along the inclusion dominates, stringers are broken by tensile fractures and boudinage at relatively shallow depth. Spacing of the boudin–bounding faults can be as close as 3–4 times the thickness of the stringer. In contrast, salt shortening along the inclusion may lead to folding or thrusting of stringers.

Beschreibung: The Late Jurassic–Cretaceous Parentis Basin (Eastern Bay of Biscay) illustrates a complex geological interplay between crustal tectonics and salt tectonics. Salt structures are mainly near the edges of the basin, where Jurassic–Lower Cretaceous overburden is thinner than in the basin centre and allowed salt anticlines and diapirs to form. Salt diapirs and walls began to rise reactively during the Late Jurassic as the North Atlantic Ocean and the Bay of Biscay opened. Some salt-cored drape folds formed above basement faults from the Upper Jurassic to Albian. During Albian–Late Cretaceous times, passive salt diapirs rose in chains of massive salt walls. Many salt diapirs stopped growing in the Mid-Cretaceous when their source layer depleted. During the Pyrenean orogeny (Late Cretaceous–Cenozoic), the basin was mildly shortened. Salt structures absorbed almost all the shortening and were rejuvenated to form squeezed diapirs, salt glaciers and probably subvertical welds, some of which were later reactivated as reverse faults. No new diapirs formed during the Pyrenean compression, and salt tectonics ended with the close of the Pyrenean orogeny in the Middle Miocene. Using reprocessed industrial seismic surveys, we document how salt tectonics affected the structural evolution of this offshore basin largely unknown to the international audience.

Beschreibung: Over the last 10 years there has been a unique regulator-led programme involving extensive development of regional groundwater models across England and Wales for water resources purposes by the Environment Agency for England and Wales. Eight regionally managed programmes are underpinned by a framework, which has allowed a coordinated national approach. The main uses of the models are for catchment abstraction management and licensing. Models have also assisted in monitoring network design, investigating groundwater quality and implementing groundwater source protection zones. A five-yearly review of the programmes recognized the importance of benefit realization and stakeholder involvement as well as technical good practice. The programme already delivered provides a solid foundation for supporting the management decisions required in areas such as climate change mitigation and integrated catchment management using appropriate tools at a time of rapid organization change and financial uncertainty.

Beschreibung: Earthquake catastrophe models combine simulated earthquake hazard intensity parameters, such as ground-shaking intensity and liquefaction potential, with spatial data layers describing the geography and vulnerability of exposed assets at risk (property, populations and infrastructure) to calculate the probability of loss. There is significant scope for applying catastrophe models to disaster relief planning, risk mitigation and financing, especially for earthquake-prone developing economies in Asia. Potential uses of earthquake catastrophe models in these areas include the following: - Estimating probable levels of damage across an area resulting from a range of possible earthquake events. These estimates are useful in assessing the scale of the response required when an earthquake event actually occurs and for devising a realistic plan for the disaster response effort. - Quantifying the humanitarian and economic benefit of introducing or upgrading existing risk mitigation measures in advance of their introduction; and assessing the loss potential of possible sites for future infrastructure and/or industrial facilities. - Quantifying risk metrics fundamental to the pricing of financial risk transfer solutions that enable the transfer of the cost of relief and reconstruction away from the damaged national economy, thereby cushioning it from financial shock caused by major earthquake damage.

Beschreibung: The military aspects of hydrogeology can be categorized into five main fields: the use of groundwater to provide a water supply for combatants and to sustain the infrastructure and defence establishments supporting them; the influence of near-surface water as a hazard affecting mobility, tunnelling and the placing and detection of mines; contamination arising from the testing, use and disposal of munitions and hazardous chemicals; training, research and technology transfer; and groundwater use as a potential source of conflict. In both World Wars, US and German forces were able to deploy trained hydrogeologists to address such problems, but the prevailing attitude to applied geology in Britain led to the use of only a few, talented individuals, who gained relevant experience as their military service progressed. Prior to World War II, existing techniques were generally adapted for military use. Significant advances were made in some fields, notably in the use of Norton tube wells (widely known as Abyssinian wells after their successful use in the Abyssinian War of 1867/1868) and in the development of groundwater prospect maps. Since 1945, the need for advice in specific military sectors, including vehicle mobility, explosive threat detection and hydrological forecasting, has resulted in the growth of a group of individuals who can rightly regard themselves as military hydrogeologists.

Beschreibung: This article explores the institutional responses to the volcanic crises and related problems encountered during the 1994 and 2006 eruptions of the Merapi Volcano, Indonesia. It also illustrates traditional responses to the volcanic crisis led by the local community and provides recommendations to encourage a comprehensive institutional volcanic crisis management including community-based response. This study aims to understand and to explain the gap between institutional responses and the community's perception during pre- to post-crisis situations. Interviews, questionnaires and focus group discussions revealed that top-down institutional responses to the volcanic crisis are not fully appropriate in regions with a high cultural perception. Working with the community is an ideal solution to minimize the gap between the government, scientists, non-governmental organizations and the community itself. A community-based methodology combined with natural hazard studies generates comprehensive risk and crisis management.

Beschreibung: The recent 2011 Tohoku Tsunami showed yet again the devastating impact that these events can have on coastal communities. Even prior to the 2004 Indian Ocean Tsunami there had been a growing awareness of the need to document a record of past tsunamis for risk reduction purposes. The bulk of such early databases were based on historical data. Only in recent years have palaeotsunami databases started to be collated. When one considers that the Pacific region accounts for 85% of known historical tsunamis worldwide, it is unsettling that we have only documented 11 palaeotsunamis throughout all Pacific Island countries (PICs). The way forward to enhance our understanding of palaeotsunamis, and to better understand the magnitude and frequency of events from local, regional and distant Pacific sources, is to gather data from each PIC. By collating data from each island it should be possible to map the spatial and temporal distribution of past events over the last several thousand years throughout the entire Pacific region. These data will provide the essential baseline information needed for achieving more effective disaster risk reduction for PICs.

Beschreibung: The German Army developed a military geological organization during World War I largely as a response to near-static battlefield conditions on the Western Front, in Belgium and northern France. In 1916 it was assigned to support military survey, but in late 1918 it was reassigned to the engineer branch of the Army. It contained over 350 geologists and associated technicians by the end of the war. Military geologists contributed advice on engineering geology and hydrogeology (principally on water supply, but also site drainage). They compiled a large number and wide range of groundwater prospect maps to guide military planning, at scales typically from 1:250 000 to 1:25 000. They contributed advice to guide effective use of groundwater by means of dug or bored wells, ‘Abyssinian’ driven tube wells, and protected capturing of springs. Field hygiene was of particular concern, and military geologists helped to avoid contamination of groundwater, for example by appropriate siting of cess-pits and cemeteries. A few officers made use of dowsing in attempts to locate groundwater, including at least one German in support of Ottoman Turk campaigns SW from Palestine towards the British-held Suez Canal, their Austro-Hungarian allies in campaigns south against Italy and in the Balkans, but with relatively insignificant success.

Beschreibung: Over the past 100 years, hydrogeology has played a role in most military operations undertaken by the USA. The first significant application by US forces took place during World War I, on the Western Front. America's entry into World War II highlighted the need for military hydrogeologists once again, and a combination of civilian and uniformed hydrogeologists provided valuable support to the war effort, notably by terrain analysis. During the Cold War, the United States Geological Survey Military Geology Branch conducted military hydrogeological studies, and in 1985 the US Army Corps of Engineers created the Water Detection Response Team (WDRT) to provide hydrogeological expertise to military well-drilling units. During the Persian Gulf War of 1990–1991, groundwater was important for sustaining troops living in the northern Saudi Arabian desert. Operations in Bosnia and Kosovo later in that decade required the assistance of the WDRT in obtaining adequate groundwater supplies for base camps. Current military operations in Afghanistan rely on groundwater as a significant source for most US bases. In combination, uniformed and civilian geologists serving in a variety of roles to support American troops have located water supplies essential to the success of US military operations around the globe.

Beschreibung: In 2003, three British reserve army geologists contributed hydrogeological advice to assist planning for the Coalition invasion of Iraq by predicting likely groundwater and drilling conditions. In consequence, 521 Specialist Team Royal Engineers (Water Development) was deployed in theatre soon after hostilities began, to provide a water supply infrastructure for British troops. However, a speedy end to combat, and concentration of British troops in southern Iraq where surface waters were the primary source of supply, necessitated only four new boreholes. Elements of 521 STRE deployed to Afghanistan in 2006, again with hydrogeological guidance, to enhance water supplies for a Provincial Reconstruction Team and Forward Operating Base (FOB), and to develop a water supply infrastructure for the main British operational base at Camp Bastion. Local contractors were used to drill 11 wells, each to over 100 m depth, in Quaternary alluvium. Subsequently, hydrogeology was used to guide successful groundwater development at four out of five FOBs, involving 28 new boreholes, minimizing risks associated with water supply by road or helicopter, and to facilitate expansion of Camp Bastion to accommodate a surge of Coalition troops. Tasks in Afghanistan have generated the most significant British military use of hydrogeology in recent years.

Beschreibung: Finding explosive threats in complex environments is a challenge. Benign objects (e.g. rocks, plants and rubbish), ground surface variation, heterogeneous soil properties and even shadows can create anomalies in remotely sensed imagery, often triggering false alarms. The overarching goal is to dissect these complex sensor images to extract clues for reducing false alarms and improve threat detection. Of particular interest is the effect of soil properties, particularly hydrogeological properties, on physical temperatures at the ground surface and the signatures they produce in infrared imagery. Hydrogeological variability must be considered at the scale of the sensor's image pixels, which may be only a few centimetres. To facilitate a deeper understanding of the components of the energy distribution, a computational testbed was developed to produce realistic, process-correct, synthetic imagery from remote sensors operating in the visible and infrared portions of the electromagnetic spectrum. This tool is being used to explore near-surface process interaction at a fine scale to isolate and quantify the phenomena behind the detection physics. The computational tools have confirmed the importance of hydrogeology in the exploitation of sensor imagery for threat detection. However, before this tool's potential becomes a reality, several technical and organizational problems must be overcome.

Beschreibung: Project Aquatrine was the UK Ministry of Defence's Private Finance Initiative project to transfer responsibility for water supply and waste water removal to private companies. Britain was split into three geographical areas, with Package A approximately covering the area to the west of a line between the Mersey and Southampton, Package C covering the rest of England, and Package B covering Scotland. Hydrogeology was a major factor in the models used to produce financial forecasts for Package A, upon which the winning bid was based. Reconnaissance-level understanding of aquifers, water demand and the Environment Agency's view of licensing possibilities were used to produce a list of sites where water resources could be developed to replace the incumbent water suppliers. Several sites have been developed successfully, but a number of possible abstractions have failed to be realized because of hydrogeological (quality, quantity) and other causes. In the operational phase of Aquatrine, hydrogeology was used to understand the data produced by a new network of telemetred groundwater level loggers, to constrain the location of new sewage treatment works and to apply for appropriate abstraction licences when Crown Immunity under the Water Resources Act 1991 is finally lost.

Beschreibung: The Singhbhum Craton has a limited Palaeoproterozoic supracrustal record, which suggests a three-part history, comprising: a long period of high freeboard and palaeosol formation on granitoids; subsequent rift-related mafic–ultramafic volcanism and subordinate sedimentation (c. 2.25–2.1 Ga: Dhanjori and Jagannathpur basin-fills; possibly also Simlipal, Malangtoli and Ongarbira basin-fills), which overlapped locally with mafic soil formation; and a major regression at around 2.0 Ga. Following a long hiatus, the approximately 1.6 Ga Dhalbhum–Dalma succession was laid down, probably under continental conditions. This rather truncated record stands in contrast to the chronologically and geographically much more widespread supracrustal basin-fills of the Kaapvaal Craton, and there appears to be an overall poor comparison between these two early Precambrian crustal blocks. However, on Kaapvaal, three analogous events are identified: widespread approximately 2.2 Ga mafic volcanism, followed by a well-developed palaeosol and a major transgression prior to 2.05 Ga. The three shared events between the two cratons are compatible with the postulate of a global, approximate 2.45–2.2 Ga shutdown of magmatic and tectonic geodynamics, with the origin of the triumvirate directly reflecting its resumption again after about 2.2 Ga. We recognize here that a large diversity of views on Singhbhum's geodynamic history exists, predicated on a lack of precise geochronology and commonly poor outcrops, and the current hypotheses are presented with these factors in mind.

Beschreibung: Parts of two third-order Neoproterozoic (Marinoan) depositional sequences are documented in the Wilpena Group (Wonoka Formation and Bonney Sandstone) at Patawarta diapir, located in the central Flinders Ranges, South Australia. These sequences represent an overall regressive succession transitioning upwards from outer to middle wave-dominated shelf deposits to a tidally dominated barrier bar to coastal plain. The lower, middle, upper limestone and green mudstone informal members of the Wonoka Formation comprise the Highstand Systems Tract of the lower sequence. The Sequence Boundary is at the top of the Wonoka green mudstone member and is overlain by the Lowstand Systems Tract of the upper sequence, which includes the lower dolomite, sandstone and upper dolomite beds of the Patsy Hill Member of the Bonney Sandstone. The upper sequence Transgressive Systems Tract comprises the Bonney Sandstone. These units comprise one complete tapered composite halokinetic sequence (CHS). The lower halokinetic-sequence boundary is associated with the Maximum Flooding Surface of the lower depositional sequence and the upper halokinetic-sequence boundary is interpreted as the Transgressive Surface of the overlying depositional sequence where an angular truncation of up to 90° is documented.

Beschreibung: Two-dimensional plane-strain numerical experiments illustrate the effects of variable evaporite viscosity and embedded frictional-plastic sediment layers on the style of salt flow and associated deformation of the sedimentary overburden. Evaporite viscosity exerts a first-order control on the salt flow rate and the style of overburden deformation. Nearly complete evacuation of low-viscosity salt occurs beneath expulsion basins, whereas significant salt is trapped when viscosity is high. Embedded frictional-plastic sediment layers with yield strength partition salt flow and develop transient contractional structures (folds, thrust faults and folded faults) in a seaward salt-squeeze flow regime. Multiple internal sediment layers reduce the seaward salt flow during sediment aggradation, leaving more salt behind to be remobilized during subsequent progradation. This produces more seaward extensive allochthonous salt sheets. If there is a density difference between the embedded layers and the surrounding salt, then the embedded layers fractionate during deformation and either float to the surface or sink to the bottom, creating a thick zone of pure halite. Such a process of ‘buoyancy fractionation’ may partially explain the apparent paradox of layered salt in autochthonous salt basins and pure halite in allochthonous salt sheets.Supplementary material: Animated gif files of the model results are available at http://www.geolsoc.org.uk/SUP18500.

Beschreibung: The Indian shield represents a vast repository of the Palaeoproterozoic geological record. Built over the four large amalgamated Archaean nuclei (Dharwar, Bastar, Singhbhum and Aravalli–Bundelkhand) the major and minor Palaeoproterozoic sedimentary basins and supracrustal sequences in India are comparable in scale, and perhaps also in development, to those of North America, Africa, Australia and Brazil. The deformation of these supracrustal sequences, attendant metamorphism and emplacement of plutonic bodies hold important clues to their connection with major orogenies. Research in these areas has led to investigations into global correlation, which in turn has had a direct bearing on refining models of Palaeoproterozoic supercontinent assembly and break-up. This book covers various aspects of regional geology as well as broader issues of the Indian Palaeoproterozoic geology and its global context. It is an outcome of the UNESCO-IGCP 509 Palaeoproterozoic Supercontinents and Global Evolution research project.

Beschreibung: The Lichfield Permo-Triassic Sandstone aquifer is a strategic groundwater resource for the UK West Midlands. However, the flows of a number of streams have been heavily affected by abstraction. The catchment of one of these, the Leamonsley Brook, is under-drained by the Hanch Tunnel, a 5 km-long water transfer tunnel that is more than 150 years old. The Hanch Tunnel was excavated below the water-table for its entire length and is only partly lined. Regional-scale simulation of the aquifer was undertaken using a version of the USGS MODBRNCH code, which had been previously adapted to enable simulation of both open channel and pressurized pipe flow systems (the ‘Adit Code’). This paper reports on the simulation of the Hanch Tunnel, with an emphasis on the representation of this tunnel, and its effects on the groundwater flow in the Leamonsley Brook catchment. Critical aspects to consider when implementing the Adit Code are identified and discussed. The value of the application of the Adit Code for options appraisal to resolve the low-flow conditions of the Leamonsley Brook is explored.

Beschreibung: In the 1970s regional groundwater modelling began to be used in support of many hydrogeological investigations in the UK. A number of the studies were concerned with groundwater development at a regional scale in conjunctive use schemes; elsewhere the effect of pumping from aquifers on river flows or the ingress of saline water was considered. Due to the limited power of digital computers at that time, special numerical codes were often prepared for individual projects, with consequent inefficiency and inconsistency of practice. However, by the mid 1990s the need to formalize and standardize groundwater modelling projects was recognized. The Environment Agency of England and Wales prepared a strategy to manage and monitor the projects. A Template Project Brief was prepared to define the many tasks involved in groundwater studies and to clarify the roles of contractor and client (Environment Agency). In addition Guidance Notes were prepared to disseminate procedures and techniques that had resulted in successful outcomes. This paper summarizes some of the earlier studies, provides information about the Project Brief and Guidance Notes and illustrates some critical issues in groundwater modelling by reference to two case studies.

Beschreibung: The UK is a country with over 150 years of widespread exploitation of its principal aquifers for public water supply. Increasing demands, greater awareness of environmental pressures and more exacting legislation has heightened the need for quantitative models to predict the impacts of groundwater use. In the UK this has culminated in a unique national, regulator-led programme for England and Wales to develop conceptual and numerical models of the principal bedrock aquifers.The outcomes of this programme will be of interest to the international hydrogeological community, particularly as international legislation such as the European Water Framework Directive requires management of water issues across administrative boundaries with a varied cast of stakeholders.The collection of papers provides a contrast between practitioner- and research-based approaches to assess and predict the anthropogenic impacts and environmental pressures. Many insights are provided on how the regular use of groundwater models may address the environmental challenges of the future.

Beschreibung: The arcuate Singhbhum Shear Zone (SSZ) of the East Indian Shield area, fringing the Archaean Singhbhum Craton, exposes a mélange-like ensemble of polymetamorphosed and highly tectonized siliciclastic sediments, mafic–ultramafic extrusive, tourmaline-rich rocks, magnetite–apatite rocks, granites and Cu–Fe–U sulphide ores of Meso- to Palaeoproterozoic age (1.5–1.77 Ga). Metapelites from two localities in the SSZ developed the enigmatic assemblage chloritoid–biotite–garnet–chlorite, which are the first reported from India and the eighth in world occurrence. Textural studies and algebraic analyses of the phase compositions in the KFMASH system indicate the operation of the reaction, chloritoid+biotite?garnet+chlorite+H2O and this reaction has a negative slope in pressure–temperature (P–T) space. Quantitative geothermobarometry and pseudosections in the NCMnKFMASHO system indicate that this reaction occurred during prograde metamorphism that culminated at 6.3±1 kbar and 490±40 °C. The stability of the chloritoid+biotite is also sensitive to the MnO content of the bulk rock, and to the chemical potential of H2O and oxygen ( and , respectively), of the ambient fluid phase. Thrusting of continental crust in a collisional setting is invoked to explain the peak metamorphic temperatures and the clockwise P–T trajectory is construed from the petrological study of the chloritoid–biotite schist.

Beschreibung: Recent contraction in the NW Tarim Basin, China, has exhumed a thick (2–3 km) sequence of Upper Neoproterozoic to Lower Palaeozoic sediments that provide a unique insight into the early evolution of the basin. The sedimentary sequence was examined in outcrop and consists of a lower, 500-m-thick fluvial–lacustrine clastic and volcanic succession, conformably overlain by a 2000-m-thick shallow marine carbonate succession which records a major rifting event that initiated in the Late Neoproterozoic. This rifting event probably corresponds to the break-up of East Gondwana and the separation of the Tarim Block from a conjugate margin equivalent in NW Australia. The generation and infilling of rift basins creates a number of potential hydrocarbon plays, although analysis of individual play elements indicates a relatively high risk, despite the prevalence of hydrocarbons derived from the same rift sequence elsewhere in the basin.

Beschreibung: Extensive subsurface sampling of the Huqf Supergroup in the Sultanate of Oman has yielded microfossil assemblages of Cryogenian, Ediacaran and Early Cambrian age. Microfossils have been recovered from most stratigraphic units in the Huqf, including Marinoan-equivalent horizons of the Ghadir Manqil Formation (Cryogenian Abu Mahara Group), the Masirah Bay, Shuram and Buah formations of the Ediacaran Nafun Group, and the A3 (latest Ediacaran) and A6 (Early Cambrian) cycles of the Ara Group. Despite the extensive recovery of leiosphaerid acritarchs from the Shuram Formation, there is no indication of the large acanthomorphs typical of other early–middle Ediacaran assemblages. This absence suggests a relatively young (post-extinction) depositional age for the Shuram; however, the signal is complicated by local deep-water conditions and the facies-specific distribution of Proterozoic microfossils. A shallower-water sequence of undivided Nafun Group sediments preserves sphaeromorphic acritarchs in association with filamentous microfossils, fragmentary vendotaenids and possible vaucheriacean algae.

Beschreibung: The Indian Proterozoic Super Basins were part of the Northern Rim of Gondwanaland prior to its break-up along six major radial fractures. The Proterozoic rocks of these basins are extensively exposed in the northern as well as the southern parts of the Indian Peninsula. Based on recently conducted geochemical and seismic surveys within these basins, followed by well drilling in the Son Valley, Ganga Valley, and the Bikaner–Nagaur basin, it is concluded that hydrocarbons have been generated within these basins and conditions conducive to hydrocarbon accumulation exist within them. The discovery of gas within Son Valley has indicated the existence of an active Mesoproterozoic petroleum system that is likely to have continued up to Infracambrian times. Based on the correlation of Indian Proterozoic Super Basins with their analogous Chinese and Australian basins, it appears that elements of a similar petroleum system exist within these basins, together with the possibility of an active Ordovician–Silurian petroleum system within the northernmost Ganga Valley Vindhyans, where sedimentation continued up to the lower Devonian. Modelling and empirical data show that the Chambal Valley, as well as the probably trap-concealed Vindhyans, underwent intense wrenching during Neoproterozoic times, accompanied by good entrapment conditions. Even the peninsular SW Cuddapah Superbasin also appears worth exploring as an element of the Meso–Neoproterozoic petroleum system.

Beschreibung: The burgeoning oil and gas consumption in India in recent years has necessitated looking into the Proterozoic basins of India, which are sparsely explored and have a scanty knowledge base. The rationale for hydrocarbon exploration in Indian Proterozoic basins is derived from the fact that they have large basinal areas, wide geographical distribution, varied geotectonic setting and sedimentary fill. The favourable tectonic settings of these basins, pronounced biological activity, known hydrocarbon gas seepages, and subsurface commercially viable oil and gas shows in the Bikaner–Nagaur and Vindhyan basins and analogous basins throughout the world necessitate proactive exploration strategies in these basins. The basins of Bikaner–Nagaur, Vindhyan, Cuddapah and Chhatishgarh include thick Neoproterozoic/basal Lower Palaeozoic (Cambrian) successions, in addition to Palaeoproterozoic and Mesoproterozoic sequences. The Neoproterozic sediments in these basins incorporate thick successions of shale, limestone and sandstone. These successions have rich organic matter of high-quality cyanophycean (stromatolites, acritarchs and filamentous algae) affinity that is proven to be high-quality (type one) source material for hydrocarbon generation and also involved in later structurization. However, the Neoproterozoic sedimentary pack in the Bhima–Kaladgi basins is comparatively less thick, and appears to have less prospectivity. The available geological and source-rock data are reassessed for their hydrocarbon prospectivity in order to help in planning a strategy for exploration in these basins.

Beschreibung: The initial Mw7.1 Darfield earthquake sequence was centred west of Christchurch City in the South Island of New Zealand but aftershocks, including a highly destructive Mw6.3 event, eventually extended eastwards across the city to the coast. The mainshock gave rise to right-lateral strike-slip of up to 5 m along the segmented rupture trace of a subvertical fault trending 085±5° across the Canterbury Plains for c. 30 km, in agreement with teleseismic focal mechanisms. Near-field data however suggest that the mainshock was composite, initiating with reverse-slip north of the surface rupture. Stress determinations for the central South Island show maximum compressive stress σ1 to be horizontal and oriented 115±5°. The principal dextral rupture therefore lies at c. 30° to regional σ1, the classic ‘Andersonian’ orientation for a low-displacement wrench fault. An aftershock lineament trending c. 145° possibly represents a conjugate left-lateral strike-slip structure. This stress field is also consistent with predominantly reverse-slip reactivation of NNE–NE faults along the Southern Alps range front. The main strike-slip fault appears to have a low cumulative displacement and may represent either a fairly newly formed fault in the regional stress field, or an existing subvertical fault that happens to be optimally oriented for frictional reactivation.

Beschreibung: The Ceduna Sub-basin is located within the Bight Basin on the Australian southern margin. Recent structural analysis using newly acquired two-dimensional (2D) and three-dimensional (3D) seismic data demonstrates two Late Cretaceous delta–deepwater fold–thrust belts (DDWFTBs), which are overlain by Cenozoic sediments. The present-day normal fault stress regime identified in the Bight Basin indicates that the maximum horizontal stress (SHmax) is margin parallel; Andersonain faulting theory therefore suggests the delta-top extensional faults are oriented favourably for reactivation. A breached hydrocarbon trap encountered in the Jerboa-1 well demonstrates this fault reactivation. Faults interpreted from 3D seismic data were modelled using the Poly3D© geomechanical code to determine the risk of reactivation. Results indicate delta-top extensional faults that dip 40–70° are at moderate–high risk of reactivation, while variations in the orientation of the fault planes results in an increased risk of reactivation. Two pulses of inversion are identified in the Ceduna Sub-basin and correlate with the onset of rifting and fault reactivation in the Santonian. We propose a ridge-push mechanism for this stress which selectively reactivates extensional faults on the delta-top, forming inversion anticlines that are prospective for hydrocarbon exploration.

Beschreibung: Delta–deepwater fold–thrust belts are linked systems of extension and compression. Margin-parallel maximum horizontal stresses (extension) on the delta top are generated by gravitational collapse of accumulating sediment, and drive downdip margin-normal maximum horizontal stresses (compression) in the deepwater fold–thrust belt (or delta toe). This maximum horizontal stress rotation has been observed in a number of delta systems. Maximum horizontal stress orientations, determined from 32 petroleum wells in the Gulf of Mexico, are broadly margin-parallel on the delta top with a mean orientation of 060 and a standard deviation of 49°. However, several orientations show up to 60° deflection from the regional margin-parallel orientation. Three-dimensional (3D) seismic data from the Gulf of Mexico delta top demonstrate the presence of salt diapirs piercing the overlying deltaic sediments. These salt diapirs are adjacent to wells (within 500 m) that demonstrate deflected stress orientations. The maximum horizontal stresses are deflected to become parallel to the interface between the salt and sediment. Two cases are presented that account for the alignment of maximum horizontal stresses parallel to this interface: (1) the contrast between geomechanical properties of the deltaic sediments and adjacent salt diapirs; and (2) gravitational collapse of deltaic sediments down the flanks of salt diapirs.

Beschreibung: The Law of Effective Stress has found wide application in structural geology, rock mechanics and petroleum geology. The commonly used form of this law relies on an assumption of isotropic porosity. The porosity in and around fluid-saturated fault zones is likely to be dominated by tectonically induced cracks of various shapes and sizes. Previously published field and laboratory data show that these cracks occur in distinct patterns of preferred orientation, and that these patterns vary around the fault zone. This paper uses the more general form of the Law of Effective Stress which incorporates anisotropic poroelasticity to model the geomechanical response of fault zones surrounded by patterns of oriented cracks. Predictions of fault stability in response to fluid pressure changes are shown to depend on both the nature (or symmetry) of the crack pattern and the orientation of the crack patterns with respect to the in situ stress. More complete data on the porosity of natural fault zones will enable more accurate predictions of fault stability in the subsurface.

Beschreibung: Two sedimentary lithotectonic zones are traditionally recognized in the northwestern Himalayan frontal fold–thrust belt in the Nahan salient: the Lesser Himalaya Zone (LHZ) and the Sub-Himalaya Zone (SHZ). The LHZ is made up of a sequence of Proterozoic to Early Cambrian rocks and the SHZ is made up of Cenozoic rock sequences, which were deposited subsequent to the India–Asia collision. Serial balanced cross-sections show that the structural geometries become increasingly complex from independent ramp anticlines near the foreland through imbricate fan/duplex to stacked-up horses towards the hinterland. Sequential restoration suggests a structural evolution in which a foreland propagating, in-sequence thrusting event was followed by out-of-sequence thrusting in an approximately break-back style. During the out-of-sequence movement, some of the ramps formed during in-sequence thrusting were repeatedly reactivated, leading to very complex structural geometries, particularly in the LHZ. In such a complexly deformed terrain, a rigorous structural modelling approach, combined with a robust geochemical and geochronological database, should be used to carry out calibrated petroleum system modelling, and thus reduce exploration risk.

Beschreibung: Glaciogenic reservoirs and hydrocarbon systems occur intermittently throughout the stratigraphic record, with particular prominence in Neoproterozoic, Late Ordovician, Permo-Carboniferous and Late Cenozoic strata. Recent interest in glaciogenic successions has been fuelled by hydrocarbon discoveries in ancient glaciogenic reservoirs in North Africa, the Middle East, Australia and South America. Glaciogenic deposits of Pleistocene age are noteworthy for their content of groundwater onshore and potentially prospective and/or hazardous gas accumulations offshore. The abundant imprints of Pleistocene glaciations in both hemispheres can be used to reconstruct complex histories of repeated ice cover and retreat, and glacier-bed interactions, thus informing our view on the dynamics of older ice caps and predictions of future glaciations. This volume aims to provide a better understanding of glaciogenic processes, their stratigraphic record and reservoir characteristics of glaciogenic deposits. The book comprises 3 overview papers and 16 original case studies of Neoproterozoic to Pleistocene successions on 6 continents and will be of interest to sedimentologists, glaciologists, geophysicists, hydrologists and petroleum geologists alike.

Beschreibung: The southern North Sea is a shallow epicontinental sea that was glaciated several times during the Quaternary. The area is known for its remarkable record of tunnel valleys, the age and origin of which are debated. The recent availability of continuous three-dimensional seismic data between the coasts of Britain and the Netherlands provides the opportunity to establish a new seismic interpretation workflow adapted to the intracratonic glaciogenic successions. By analysing the geomorphology of the buried basal glaciogenic unconformity, four distinct major ice fronts are identified and correlated onshore. The ice fronts provide robust relative timelines, and the analysis of tunnel-valley orientations and their merging points indicates that the number of glacial phases has been underestimated. By comparing the erosion capacities of sand and chalk substrates, it is suggested that mechanical abrasion processes are also involved during tunnel-valley genesis. The methods and observations used in this study are applicable to the ancient glaciogenic record in general and constitute a basis for the sedimentological analysis of tunnel valleys.

Beschreibung: Despite a long history of investigation, several critical issues regarding the glacial history of NW Europe, particularly in currently marine areas, remain unsolved. In this study, we present a comprehensive three-dimensional (3D) seismic interpretation of an area measuring 2000 km2 in the western part of the Danish North Sea that exhibits several buried Quaternary landforms. Well data are used to assign minimum and maximum ages for the studied sedimentary succession. The most prominent buried landforms are three large-scale tunnel valleys of probable Saalian age that extend over more than 20 km across the western and southern part of the study area. These valleys most probably formed through subglacial meltwater erosion close to the termination of a former ice sheet. In the southern part of the study area, an extensive network of small-scale, dendritic seismic lineations interpreted as a palaeo-drainage system characterizes the landward termination of one major tunnel valley. This drainage system was active either contemporaneously or shortly after the development of the tunnel valley. Interpretation of this system as contemporaneous to tunnel-valley formation suggests that steady-state subglacial meltwater discharge was funnelled through a drainage system into the main tunnel valley. In contrast, interpretation of the drainage network as post-incisional points to the development of a post-glacial river system re-using the pre-existing tunnel valley as a downstream fluvial pathway. This uncertainty in the interpretation has important consequences for prediction of the rock content and reservoir characteristics of the tunnel-valley infill, in that either meltwater deposits or fluvial sediments form a considerable part of the tunnel-valley infill.

Beschreibung: Tunnel valleys formed by meltwater erosion underneath the margins of the Pleistocene ice sheets are present in high numbers in the Danish onshore area. The geographical distribution of the buried tunnel valleys is uneven, but when comparing with the substrata lithology we find a large number of valleys in areas dominated by low-permeable sediment and a smaller number in areas with highly permeable substrata. The observations point to the drainage capacity of the ice-sheet substratum as an important factor controlling tunnel-valley formation. Tunnel-valley formation appears to be favoured in areas with low-permeable substrata because meltwater drainage through the sediments is impeded, leading to the formation of a channelized subglacial drainage system. The high transmissivity in areas dominated by permeable substrata facilitates drainage of a part of the meltwater as groundwater. This causes a lowering of the subglacial meltwater pressures, and tunnel-valley formation is less likely. Once formed and filled, the tunnel valleys cause a change of the hydraulic properties of the substratum and if subglacial water pressures underneath a subsequent ice advance are sufficiently high, old tunnel valleys will be prone to reactivation.

Beschreibung: Fourteen overlapping 3D seismic reflection data sets, originally acquired by the oil and gas industry, were used to image and investigate complex networks of buried tunnel valleys in the UK sector of the Central North Sea. More than 180 individual tunnel valleys were observed and mapped to horizontal resolutions of 12–50 m and vertical resolutions of 8–10 m. The results presented here identify three recurring seismic facies that locally define stratigraphic organization from base to top of the buried tunnel valley fills: (i) high-amplitude disrupted units, (ii) a unit containing gently dipping disrupted reflections or transparent facies and (iii) well-layered continuous reflections. A comparison to similar works in the region is used to infer tunnel valley infill during changing depositional conditions from high-energy subglacial meltwater to quiet glaciolacustrine or glaciomarine environments.

Beschreibung: The Upper Ordovician glacial record of southern Jordan (Ammar Fm.) essentially consists of palaeovalley infills and of a subordinate time-transgressive fluvial to shallow-marine succession overstepping both the palaeovalleys and interfluvial areas. Valley size (depth, 60–160 m; width, 1–3 km), steep (20–50°) margins, internal organization and depositional facies point to an origin as tunnel valleys. The tunnel valleys are infilled by either fluvioglacial sandstones or fluviodeltaic coarsening-upward successions including fine-grained clayey sediments. Re-occupation of previous valleys is evident in places. At least three generations of tunnel valleys are inferred from cross-cutting relationships, although they most probably only reflect temporary standstills and minor re-advances related to the overall recession following the main glacial advance recorded in Saudi Arabia. Petrophysical measurements indicate that higher permeabilities are located in the glacially related strata (1.5–3 darcy in fluvioglacial infills), with a somewhat reduced porosity (22–28%) relative to the preglacial sandstones owing to a higher clay content, probably of diagenetic origin. Sandstone amalgamation, however, gives the fluvioglacial sandstones a high reservoir quality.

Beschreibung: Hydrothermal dolomite (HTD) bodies are known as high-quality hydrocarbon reservoirs; however few studies focus on the geometry and distribution of reservoir characteristics. Across the platform-to-basin transition of the Ramales Platform, fault-controlled HTD bodies are present. Three kinds of bodies can be distinguished based on their morphology, that is, elongated HTD corridors, a massive HTD body (Pozalagua body) and an HTD-cemented breccia body. The differences in size and shape of the HTD bodies can be attributed to differences in local structural setting. For the Pozalagua body, an additional sedimentological control is invoked to explain the difference in HTD geometry.A (geo)-statistical investigation of the reservoir characteristics in the Pozalagua body revealed that the HTD types (defined based on their texture) show spatial clustering controlled by the orientation of faults, joints and the platform edge. Porosity and permeability values are distributed in clusters of high and low values; however, they are not significantly different for the three HTD types. Two dolomitization phases (i.e. ferroan and non-ferroan) can be observed in all HTD bodies. In general, the HTDs resulting from the second non-ferroan dolomitization phase have lower porosity values. No difference in permeability is found for the ferroan and non-ferroan dolomites.

Beschreibung: The stochastic stratigraphic well correlation method considers the stratigraphic correlation of well data as a set of possible models to sample and manage uncertainty in subsurface studies. This method was applied to the Malampaya buildup (a well documented offshore gas field located NW of the Palawan Island, Philippines), aged upper Eocene to lower Miocene. Previous studies highlight that rock petrophysical properties are mainly controlled by diagenesis. Correlation rules are thus developed in order to adapt the stochastic stratigraphic well correlation method to the study of diagenetic units. These rules are based on wireline log shape and diagenetic units types. Four stratigraphic correlation models are generated using the proposed correlation method: a deterministic one corresponding to the most probable model considering only well data and three stochastic ones. These correlation models are bound with geostatistical methods to build static reservoir models. Synthetic seismic profiles are computed from facies models conditioned to acoustic impedance models. It leads to comparable seismic amplitude images, highlighting the importance of considering several well correlation models for one given seismic survey. Stochastic stratigraphic correlations are shown to have a first-order impact on reservoir unit characterization, rock volumes and fluid flow response on the reservoir model.

Beschreibung: Although karstic networks may have a major impact on fluid flow in reservoir characterization, they exhibit great intrinsic heterogeneity that makes their characterization very complex. This work proposes an integrated workflow to study and stochastically simulate karstic networks. This approach is based on the study of outcropping caves. Topological and geometrical parameters are automatically extracted from cave surveys. The extracted geometrical parameters are used to determine the input parameters of the stochastic simulations. These simulations utilize a structure-based, pixel-based and geostatistical approach. To check for consistency, a procedure is proposed to compare the topological and geometrical parameters of observed and simulated karst networks using multivariate analyses. The proposed integrated workflow has been successfully applied to a real case study involving karsts in Jurassic limestone from the south of France. The obtained karstic networks reproduce observed topological and geometrical parameters even when the employed simulation approach relies solely on geometrical parameters.

Beschreibung: The South American record of remagnetizations is linked to specific events of its tectonic history stretching back to Precambrian times. At the Ediacaran–Cambrian time interval (570–500 Ma), the final stages of the western Gondwana assemblage led to remagnetization of Neoproterozoic carbonates within the São Francisco–Congo Craton and at the border of the Amazon Craton, along the Araguaia–Paraguay–Pampean Belt. From the late Permian to early Triassic, the San Rafaelic orogeny and the emplacement of the Choiyoi magmatic province was responsible for widespread remagnetizations in Argentina and Uruguay. Cretaceous remagnetization has also been documented in Brazil and interpreted to result from magmatism and fault reactivations linked to the opening of the South Atlantic Ocean. We present a review of these widespread remagnetization events principally based on palaeomagnetic data and, when available, on rock magnetic and radiogenic isotope age data. This study gives an overview of the geographical distribution of the remagnetization events in South America, and provides important clues to better understand the geodynamic evolution of the South American plate at these times. In addition, magnetic mineralogy data for the different case studies presented here constrain the physical–chemical mechanisms that led to partial or total resetting of magnetic remanences in sedimentary rocks.

Beschreibung: The Devonian Alamo Breccia is a thick (〈30–130 m) unit, interpreted as a bolide impact deposit, which is bracketed by marine carbonates. Samples were collected within the breccia and above/below the breccia for a contact test to determine if the breccia acted as a conduit for fluids that could have caused the widespread chemical remanent magnetizations (CRMs) present in Palaeozoic Era rocks in Nevada. The carbonates above, below and in the breccia contain a Cretaceous Period syn-tilting CRM that resides in pyrrhotite and a pre-tilting late Palaeozoic Era CRM that resides in magnetite. The contact test is negative. Despite these results, diagenetic alteration by externally derived fluids is interpreted as the most likely mechanism of remagnetization. This hypothesis is supported by 87Sr/86Sr values in the breccia and surrounding rocks that suggest alteration by fluids with a radiogenic signature. The fluids were not localized in the breccia but are interpreted to have moved pervasively through the rocks. The results differ from some other studies that found that fluids caused localized CRMs around fluid conduits.

Beschreibung: Authigenic formation of fine-grained magnetite is responsible for widespread chemical remagnetization of many carbonate rocks. Authigenic magnetite grains, dominantly in the superparamagnetic and stable single-domain size range, also give rise to distinctive rock-magnetic properties, now commonly used as a ‘fingerprint’ of remagnetization. We re-examine the basis of this association in terms of magnetic mineralogy and particle-size distribution in remagnetized carbonates having these characteristic rock-magnetic properties, including ‘wasp-waisted’ hysteresis loops, high ratios of anhysteretic remanence to saturation remanence and frequency-dependent susceptibility. New measurements on samples from the Helderberg Group allow us to quantify the proportions of superparamagnetic, stable single-domain and larger grains, and to evaluate the mineralogical composition of the remanence carriers. The dominant magnetic phase is magnetite-like, with sufficient impurity to completely suppress the Verwey transition. Particle sizes are extremely fine: approximately 75% of the total magnetite content is superparamagnetic at room temperature and almost all of the rest is stable single-domain. Although it has been proposed that the single-domain magnetite in these remagnetized carbonates lacks shape anisotropy (and is therefore controlled by cubic magnetocrystalline anisotropy), we have found strong experimental evidence that cubic anisotropy is not an important underlying factor in the rock-magnetic signature of chemical remagnetization.

Beschreibung: Outcrop studies integrated with subsurface data of core, cuttings and different well logs were used to investigate reservoir characteristics of the Middle–Late Eocene Pila Spi Formation at Taq Taq oil field of Kurdistan Region of northeastern Iraq. Reservoir studies include petrographic investigations, microfacies analyses and petrophysical evaluation in an attempt to provide an insight regarding the reservoir potential.The Pila Spi Formation is subdivided into four distinctive lithofacies (P1–P4), characterized by dolostones, dolomitic limestones and limestones.Several types of dolomite were recognized ranging from early diagenetic fenestral fine crystalline to late diagenetic coarse crystalline dolomite, which had positively influenced the reservoir characteristics by enhancing inter-crystalline, intra-skeletal and micro-vug porosity, especially for lithofacies units P2 and P3.Reservoir porosity is heterogeneous in distribution and ranges from 5 to 20%. Using porosity cut-off values of 8.2%, and water saturation cut-off values of 24%, six porosity units were identified from top to bottom (PU1–PU6). The best unit is PU2 (15 m thick), which is characterized by medium crystalline dolomite mosaic with average effective porosity of 21.5%. Permeability ranges between 0.1 and 1 md.Flow unit differentiation is discussed in term of porosity–permeability cross-plot and reservoir pore-throat classification (R35). Results indicate that most of the Pila Spi reservoir is of micro-port (matrix) flow type. However, reservoir quality enhancement is attributed to fracturing.

Beschreibung: Problems experienced by armoured fighting vehicles (‘tanks’) crossing soft ground became apparent during World War I. These were avoided early in World War II by the use of ‘going’ maps in North Africa from 1940 to 1943, but when operations moved to NW Europe it was realized that there would be the additional problem of changes in ground conditions due to variations in soil moisture according to the weather. This led to an investigation into factors controlling the movement of tracked vehicles over water-softened ground, beginning in July 1944 with the establishment of the ‘Mud Committee’, tasked to consider problems in light of recent developments in the (then) new science of soil mechanics. Contemporary ideas, as applied to building and road construction, were found to be inapplicable, and attention was therefore focused on empirical trials. The Committee faced the constant problem of balancing the requirement for short-term results with the need for long-term research. As a result, it failed to meet many of its objectives by the end of hostilities, but its work did provide a sound basis for the development of a method of classifying soils for military purposes and for future work on track design.

Beschreibung: Numerical modelling of a rapid, partial destabilization of Anak Krakatau Volcano (Indonesia) was performed in order to investigate the tsunami triggered by this event. Anak Krakatau, which is largely built on the steep NE wall of the 1883 Krakatau eruption caldera, is active on its SW side (towards the 1883 caldera), which makes the edifice quite unstable. A hypothetical 0.280 km3 flank collapse directed southwestwards would trigger an initial wave 43 m in height that would reach the islands of Sertung, Panjang and Rakata in less than 1 min, with amplitudes from 15 to 30 m. These waves would be potentially dangerous for the many small tourist boats circulating in, and around, the Krakatau Archipelago. The waves would then propagate in a radial manner from the impact region and across the Sunda Strait, at an average speed of 80–110 km h-1. The tsunami would reach the cities located on the western coast of Java (e.g. Merak, Anyer and Carita.) 35–45 min after the onset of collapse, with a maximum amplitude from 1.5 (Merak and Panimbang) to 3.4 m (Labuhan). As many industrial and tourist infrastructures are located close to the sea and at altitudes of less than 10 m, these waves present a non-negligible risk. Owing to numerous reflections inside the Krakatau Archipelago, the waves would even affect Bandar Lampung (Sumatra, c. 900 000 inhabitants) after more than 1 h, with a maximum amplitude of 0.3 m. The waves produced would be far smaller than those occurring during the 1883 Krakatau eruption (c. 15 m) and a rapid detection of the collapse by the volcano observatory, together with an efficient alert system on the coast, would possibly prevent this hypothetical event from being deadly.

Beschreibung: The SW sector of Mount Natib, a potentially active volcano in the Bataan volcanic arc in western Luzon, is the site of a mothballed nuclear power plant that members of the national legislature have proposed to activate. Detailed geological fieldwork was conducted to assess the capability of the volcano and to identify any volcanic hazards it might pose to the nuclear plant. The nearest eruptive centre is 5.5 km away from the plant. SW Natib Volcano is underlain by lava flows, lahar deposits and at least six pyroclastic density current (PDC) deposits, three directly underlying the nuclear reactor facility. A fault trending N30°E is aligned with the Lubao Fault, a capable fault NE of the volcanic edifice. Radon emissions at the traces of these faults are high and comparable to those at known active faults. An associated thrust fault at the nuclear site cuts through lahars up to the ground surface. The results presented here can be used for general hazard preparedness of local communities, and may assist the government to decide whether or not to recommission the nuclear power plant.

Beschreibung: A powerful earthquake off Sumatra on 26 December 2004 set off the most disastrous tsunami to impact on the coasts and coastal communities of the Indian Ocean. Coastal tourism in Thailand, Sri Lanka and the Maldives was significantly affected. Examples from Phuket Island, Khao Lak and Ko Phi Phi Don, Thailand, show the variation in the impacts, recovery and resilience of Thai tourist coasts, focusing primarily on beach recovery and the reconstruction of the tourist industry. As priority was given to Phuket Island, tourism recovered after 1 year. Khao Lak was the worst affected and has yet to fully recover. Ko Phi Phi Don recovered but is plagued by land-use problems. Various mitigation measures have been implemented to increase the resilience of the tourist coasts. However, the resilience of the Thai tourist coasts in the event of a future tsunami is questionable.

Beschreibung: The success of military mining is inherently controlled by subsurface conditions. Military mining may be offensive (i.e. intended to breach enemy fortifications at the ground surface by explosive detonation), defensive (counter-mining to destroy enemy mine galleries) or passive (to provide troops with underground protection from bombardment). The geology of the British Sector of the Western Front in World War I varied from the Palaeogene–Neogene sediments of the Flanders Plain in Belgium to the late Cretaceous chalks of Picardy and Artois in northern France, all with intermittent Quaternary cover. In Flanders, British mining operations commenced in late 1914. Passive mining created shallow dugouts and isolated shelters, and offensive mines also tended to be shallow, rapidly dug, and of low engineering impact. By 1915, with the war above ground now largely in stalemate, the impetus for more extensive mining grew, leading to the high point of offensive mine warfare with detonations that initiated the Battle of Messines on 7 June 1917. Development of mine warfare required engineering innovations such as ‘tubbing’ to deal with major groundwater problems presented by variation in the permeability of the sediments, as can be illustrated by two examples from the battleground of Ypres (Ieper).

Beschreibung: The first British Army hydrogeologist to be deployed as such on a battlefield was Lieutenant W.B.R. King, in June 1915 on the Western Front. There, the British Expeditionary Force, in Belgium and northern France, expanded at its peak to five armies: 1.5 million men and 0.5 million horses/mules, each man/animal requiring on average 10 gallons (45 l) per day of potable water. A ‘Water Boring Section Royal Engineers’ was eventually raised for each army, equipped with American-made ‘portable’ drilling rigs, and utilizing air-lift pumps. These innovations and King's pioneering ‘water supply’ maps facilitated the development of the British Army's first operational ability to exploit groundwater from deep aquifers, primarily those in Cretaceous Chalk, by drilling 〉470 boreholes. Additionally, in 1915, a report by three ‘British’ Geological Survey officers helped guide limited boring within Allied amphibious landing areas on the Gallipoli Peninsula, Turkey. A civilian water adviser, Arthur Beeby Thompson, transferred from Gallipoli to the Balkans in January 1916 and thereafter used geology to guide significant groundwater abstraction by siting 125 military boreholes and 211 Norton tube wells. From 1915, the Director of the Geological Survey of Egypt, W.F. Hume, provided similar guidance for campaigns from Egypt into Palestine.

Beschreibung: In the latter part of the 18th century some of Britain's eastern coastal defences, although strategically well-positioned, were vulnerable because of the lack of a secure water supply. The military engineer Captain Thomas Hyde Page was tasked with identifying any water resources within the confines of the forts and garrisons that might be developed. At Sheerness he supervised the sinking of a deep, large-diameter well through the London Clay, which tapped water in underlying sands. The idea of a deep well was possibly influenced by the results of deepening a well at nearby Queenborough Castle some 60 years before. At Landguard Fort he constructed an infiltration gallery that skimmed water from the upper surface of a thin freshwater lens. At Harwich he sank two simple shallow wells to abstract water from beneath the London Clay. At each locality he used a different solution appropriate to local hydrogeological conditions. Although some of his ideas were outdated, he recognized that fresh water appeared to be floating on underlying salt water and speculated that this might be the result of differences in specific gravity. His work was important in publicizing the use of groundwater and foreshadowed the major developments of the following century.

Beschreibung: The São Paulo Plateau in the deepwater Santos Basin is the site of numerous recent pre-salt petroleum discoveries. The area is characterized by a thick sequence of layered evaporites comprising primarily halite, with subordinate anhydrite and carnalite and trace amounts of other minerals. The sequence is divided into six stratigraphic packages: three relatively competent beams containing the bulk of the stronger anhydrite and three relatively weak detachment layers. Observed structural styles range from the simple to the complex, including: upright open folds, inclined thrusted folds, recumbent isoclinal folds, sheath folds and superposed folds. Multiple detachments lead to polyharmonic folding, disharmonic folding and overtightened folds. Major anticlinal structures contain acoustically transparent material surrounding disrupted, highly deformed pieces of the lower two beams. The deformation is non-coaxial, with anticlines forming a polygonal pattern and fold hinges that are highly curvilinear. The São Paulo Plateau is a contractional province that formed in response to proximal extension at the Albian Gap during convergent gravity gliding/spreading of the margin. Shortening possibly began during the waning stages of evaporite deposition, but the bulk of the movement occurred during the Santonian–Mid-Eocene. The evaporite sequence shortened much more than the cover because of extreme updip attenuation and consequent basinwards flow beneath the cover; deeper levels of evaporite exhibit more shortening due to strain partitioning across internal detachments.

Beschreibung: The Eocene Carroza Formation in La Popa Basin, Mexico, represents fluvial sedimentation in a shortening-influenced salt-withdrawal minibasin, termed the Carroza Syncline. The Carroza Syncline lies adjacent to the La Popa salt weld, which was formerly a passively-rising salt wall that was shortened during the Hidalgoan Orogeny in Late Cretaceous and Palaeogene time. The Carroza Formation displays distinct upsection changes in fluvial facies distribution and geometry of halokinetic drape folding. Fluvial channel distribution changes upwards from widespread thin, broad channels with variable palaeocurrents in the lower part of the formation to thick, stacked channels concentrated in the hinge of the Carroza Syncline with weld-parallel palaeocurrent directions in the upper part. The upper and middle members of the Carroza contain debris-flow facies derived from diapir roof strata and the diapir itself. The style of halokinetic drape fold upturn and thinning towards the weld changes upsection from a broad (800–1500 m) to a narrow (50–200 m) zone, where upper Carroza strata are overturned and in direct contact with remnant gypsum along the weld. The upsection changes in fluvial facies distribution and geometry reflect an overall decrease in local sediment-accumulation rates relative to salt-rise rates controlled by both Hidalgoan shortening and passive diapirism.

Beschreibung: The kinematics of regional-scale salt flow in the northern Gulf of Mexico is analysed using: (i) a map of shelf-break contours at the termination of successive depositional episodes; (ii) the location and geometry of large-scale structures of the slope domain as imaged by seismics; and (iii) digital slope bathymetry. In the north margin, salt has flowed towards the SW since the Cretaceous with three main stages of development prior to, during and after a massive salt extrusion in the Early Miocene time. The corresponding sequence of structural development is discussed using a laboratory model. Contrary to all previous interpretations that invoked sedimentary loading as the main driving force, the analysis of regional-scale salt flow implies that the salt tectonics of the northern Gulf of Mexico is predominantly controlled by gliding above the margin dip. The SW-directed salt flow indicates that the north margin of the northern Gulf of Mexico trends NW–SE, in agreement with plate kinematic models in which the Yucatan continental block has undergone a 45–60° dextral rotation relative to its present orientation.

Beschreibung: This study integrates seismic interpretation and 3D analogue experiments monitored by digital image correlation techniques to investigate the evolution of the salt structures and the related depositional systems in the Laurentian Basin offshore Atlantic Canada. During the late Triassic, a layer of more than 3 km thick salt was deposited locally in a set of interconnected rift half-grabens forming a 50–70 km wide evaporite basin in the northern part of the Scotian Basin salt provinces. High sediment input in the Jurassic and early Cretaceous mobilized the salt into complex salt tectonic features, which suggest four kinematic domains with: (1) salt welds and pillows; (2) extensional diapirs and canopies; (3) contractional diapirs and folds; and (4) allochthonous salt nappe. The landward grabens trapped most of the Early Jurassic sediments by passive downbuilding into the salt with local extension. The expelled salt has been evacuated basinwards into a large contractional salt massif. The rapid advance of the allochthonous nappe was coeval with the Late Jurassic extensional collapse of the inflated salt massif due to seaward sediment progradation. Late Cretaceous and Tertiary progradation over the salt nappe caused extensional deformation with growth faulting and formation of minibasins on the secondary salt detachment level.

Beschreibung: The Papathoma Tsunami Vulnerability Assessment (PTVA) model offers a GIS (geographical information system)-based method of estimating the vulnerability of buildings to a potential tsunami threat. In the absence of fully validated building fragility curves, it provides an effective means of identifying vulnerable buildings/populations and estimating the loss associated with a tsunami. However, the PTVA model is limited by a number of factors, including a poor representation of the tsunami hazard, insufficient field testing/validation, and a data intensive and highly qualitative framework. These limitations significantly reduce its capacity as an accurate and practical tool for end users, such as emergency services and community planners. Presented in this paper is an extensive review of the PTVA methodology and recommendations on how the PTVA model can be improved to address the needs of end users. It is argued that the most recent version of the PTVA model, PTVA-3, offers the best available method for assessing the vulnerability of buildings to tsunamis. As such, the future development of new, and the refinement of existing, GIS-based tsunami vulnerability assessment techniques should consider the PTVA-3 model as the baseline.

Beschreibung: In London, groundwater abstractions for public supply are predominantly from the Chalk aquifer. However, water resource pressures put existing abstractions at risk and often require complex analysis to support new source development. Thames Water develops and uses regional groundwater models for such analysis to support communication with stakeholders such as the Environment Agency, the environmental regulator of England and Wales. Using two case studies, the importance of regional models as Thames Water assets is demonstrated. While Thames Water has developed regional models as a context for sub-catchment scale analysis of groundwater source development, they are subsequently used to address other issues. As a result, the models are updated regularly, enhancing both conceptual understanding and calibration. These models cost less than 1% of the capital cost of new water source schemes. However, as they are enhanced and applied more widely, the models accrue further value as active decision support tools. Regional model usage to investigate a range of local systems and interactions is of particular value to Thames Water. In this regard, it is important to appreciate and promote the clarity and consistency generated when stakeholder-specific issues can be analysed within an agreed regional model framework.

Beschreibung: Halokinetic sequences are unconformity-bound packages of thinned and folded strata adjacent to passive diapirs. Hook halokinetic sequences have narrow zones of deformation (50–200 m), 〉70° angular discordance, common mass-wasting deposits and abrupt facies changes. Wedge halokinetic sequences have broad zones of folding (300–1000 m), low-angle truncation and gradual facies changes. Halokinetic sequences have thicknesses and timescales equivalent to parasequence sets and stack into composite halokinetic sequences (CHS) scale-equivalent to third-order depositional cycles. Hook sequences stack into tabular CHS with sub-parallel boundaries, thin roofs and local deformation. Wedge sequences stack into tapered CHS with folded, convergent boundaries, thicker roofs and broad zones of deformation. The style is determined by the ratio of sediment-accumulation rate to diapir-rise rate: low ratios lead to tabular CHS and high ratios result in tapered CHS. Diapir-rise rate is controlled by the net differential load on deep salt and by shortening or extension. Similar styles of CHS are found in different depositional environments but the depositional response varies. CHS boundaries (unconformities) develop after prolonged periods of slow sediment accumulation and so typically fall within transgressive systems tracts in shelf settings and within highstand systems tracts in deepwater settings. Sub-aerial settings may lead to erosional unroofing of diapirs and consequent upward narrowing of halokinetic deformation zones.

Beschreibung: History has repeatedly demonstrated the potentially negative influence of near-surface hydrology on military mobility. Increased moisture and saturation in soil results in a transition from solid to somewhat liquid states. As soil approaches the liquid state, the shear strength available for supporting traffic of ground vehicles or aircraft diminishes. Historical engagements elucidate the importance for armies to recognize soil conditions that could compromise manoeuvre. Since World War II, the US Army has pursued research aimed at equipping soldiers with the tools and knowledge needed to account for the impact of near-surface hydrology on mobility. Significant portions of the research have been focused on characterizing soil trafficability as a controlling factor in ground vehicle mobility and on developing methods for rapidly assessing soil conditions to ensure adequate bearing capacity for expediently constructed roads and airfields. In contrast, hydrological conditions can also produce extremely dry soil with potential for surface layers to break down under ground vehicle and aircraft traffic loadings, resulting in a propensity for extreme dust generation, an entirely different problem for military mobility that the research has also been addressing. Mobility problems associated with these adverse soil conditions have not been eliminated, but the research has produced significant advancements.

Beschreibung: Salt–sediment interplay in the Santos Basin is investigated integrating seismic interpretation, kinematic restoration and analogue modelling. Deformation within the post-salt sequence results from thin-skinned gravitational gliding and spreading, driven primarily by halokinesis, greatly affected by massive sediment inflows. The impressive landward-dipping listric Cabo Frio Fault controls the major depocentres updip, whereas salt-cored folds accommodate downdip shortening. Sediment supply from confluent directions creates a complex interference pattern of superposed folds with intervening polygonal minibasins. A new structure is identified (termed the ‘Ilha Grande Gravitational Cell’), a linked system of updip extension and downdip contraction detached on salt, comprising the Cabo Frio Fault and minibasins. It moves to the SE, with eastern and western borders suggesting lateral gradients of slippage. This thin-skinned feature results from the differential load imposed by a thick prograding wedge over the ductile salt and is independent of pre-salt structures. The post-salt sequence moves basinwards due to halokinesis, thereby changing position relative to the pre-salt sequence, which implies that any present-day correspondence between pre- and post-salt structures may not attest to linkage in the past. Application of kinematic restoration techniques allows the true position and geometry of the key elements through time, improving petroleum systems assessment.

Beschreibung: The onshore Ukraine Dnieper–Donets Basin (DDB) is a large partially inverted late Palaeozoic intracratonic basin. Rifting began in the late Devonian when two evaporite sequences were deposited, and Carboniferous post-rift thermal sag was accompanied in some areas by some extension. Although important quantities of Devonian salt are calibrated by wells and diapirs have been documented, classic salt diapirs are probably not as common as suggested by the literature. Indeed, in several parts of the basin salt movement was stopped and buried by up to 5 km of overburden. Four important tectonic events related to salt movement have been documented over the DDB: Tournaisian–Early Visean extension, Middle Serpukhovian extension, Late Carboniferous–Early Permian movements mostly documented recently as extension and uplift and Alpine compression. Seismic imaging of the basin has not traditionally been of the highest quality, but the reprocessed seismic data made available over several parts of the DDB as part of a Ferrexpo/RDS multi-licence project has enabled three new structural observations of the basin to be made. Firstly, it is proposed that basin margin extension, facilitated by listric faulting with thin-skinned décollement on Devonian salt and exemplified by well-imaged Tournaisian syntectonic wedges, is linked to thick-skinned partial inversion of some basement rift faults. Secondly, it is proposed that these thick-skinned faults acted as obstacles or buffers, where monoclines began to develop. These folds were exaggerated by the later tectonic movements. Thirdly, we propose that these linked tectonic events may have been caused by pulses of sag which punctuated the Lower Carboniferous post-rift thermal sag process. These three observations fit neatly with published interpretations of Tournaisian–Lower Visean and Middle Serpukhovian extension. Finally, however, a literature review and new seismic interpretation also clearly show that Late Carboniferous–Early Permian movements inverted marginal listric faults and their Tournaisian wedges, and also inverted the downdip thick-skinned faults causing the monoclines to further develop prior to the Alpine overprint. This, contrary to many published papers over the last 15 years or so, suggests that this Late Carboniferous–Early Permian event brought shortening rather than extension to the DDB.

Beschreibung: The Central European Basin System (CEBS) includes the former Northern and Southern Permian Basins together with superimposed Meso-Cenozoic sub-basins and contains a thick layer of Upper Permian (Zechstein) salt. This salt was mobilized in response to several post-Permian tectonic events. In order to analyse the regional relationship between the structural pattern of the Meso-Cenozoic sedimentary cover and the distribution of the Upper Permian salt, a 3D structural model of the CEBS has been constructed. In this model, the Permian salt is resolved as an extra layer for the entire basin system. According to the 3D structural model, the salt layer is strongly deformed as a result of halokinetic activity. The thickest salt is localized within salt walls and diapirs, reaching up to 9 km of thickness. A regional structural 3D analysis of the overburden in relation to underlying ductile salt demonstrates that the geometry of the sedimentary cover is strongly complicated by a variety of salt structures. The withdrawal of the Permian salt appears to have played a key role in both deposition and deformation of Meso-Cenozoic deposits in addition to tectonically forced regional subsidence.

Beschreibung: The allochthonous Tertiary salt of the Garmsar salt nappe extruded from where the most southerly point of the Alborz Mountain front is offset by the Zirab–Garmsar strike-slip fault. We used eleven descending Advanced Synthetic Aperture Radar (SAR) images, acquired by the European Space Agency's ENVISAT satellite from 2003 to 2006, to map surface displacement over 23 increments ranging in time from 30 to 2 months. A 30 month SAR interferogram of the area shows that the regional folds and faults are active south of the mountain front, but are dampened by the allochthonous salt that otherwise appears to be merely degrading at rates that vary with the season. Interferograms for shorter epochs display different patterns of fault blocks in the country rocks that rose and fell with the seasons. By relating surface displacements mapped in these interferograms to the contemporaneous seismic record, we find that seismic faults reactivate repeatedly while their kinematics may have inverted on remarkably short timescales. Seismic disturbances propagate very slowly and faults are longer than expected for earthquakes with ML〈3.5, indicating that the regional strains are more aseismic than anticipated by earlier studies.

Beschreibung: Stratigraphical, sedimentological and structural data and a Bouguer gravity map of Medjez-El-Bab (MEB) in Northern Tunisia are used to illustrate a Cretaceous example of salt extrusion on a passive continental margin. Located just south of the Teboursouk thrust front (a preferential décollement surface used by the continuous Tertiary shortening in this area), the MEB structure is a simple N40°E box anticline. Removing the two Tertiary foldings (Eocene and Miocene) leads to the exposure of the original feature of a simple submarine ‘salt glacier’. The Triassic salt rocks appear as an Albian interstratified body between two Cretaceous series with stratigraphic normal polarity, suggesting a bedding parallel extrusion (at the sediment–water interface) of the Triassic salt in Cretaceous times. The formation of such salt extrusions are associated with extensional faulting (probably both in the cover and basement), the presence of a slope and basinwards salt flow. This scenario is similar to the allochthonous salt described in other salt provinces, characterizing passive margins.

Beschreibung: Six regional recharge and groundwater models have been recently developed of the Chalk and Upper Greensand from Dorset to Kent. Updated Chalk stratigraphy and mapping have improved understanding of geological structure and the development of preferential groundwater flow pathways along hardground horizons. Where shallow dipping folds bring these into the zone of active groundwater flow, extensive ‘underdrainage’ may result in marked differences between surface and groundwater catchments. Hardgrounds and marls are also associated with spring discharges, as are some faults and the clay formations that underlie or confine the aquifer system. Higher specific yield within the Upper Greensand helps support summer baseflow, as do local groundwater discharges from augmentation schemes, watercress and fish farm operations. The aquifer system has been successfully modelled using the ‘variable hydraulic conductivity with depth’ version of MODFLOW. Depths of secondary permeability development have been distributed according to ground and groundwater level data. Interfluve–valley contrasts overlie a base hydraulic conductivity set according to the formation saturated at the water table and enhanced by active hardgrounds. Local parameter overrides may also be needed. The Wessex Basin conceptual and numerical model is described before summarizing similarities and contrasts from the other five regional model areas.

Beschreibung: The Mesoarchaean–Palaeoproterozoic stratigraphic record of the Singhbhum crustal province, eastern India, implies sedimentation and volcanism in a changing tectonic scenario, and thus assumes immense geological significance. Although efforts have been made by many researchers in the past several decades to summarize various geological aspects of the Singhbhum crustal province, a critical synthesis of various stratigraphic issues was long overdue. The present contribution is an updated critical synthesis of the Mesoarchaean–Palaeoproterozoic stratigraphic record of the Singhbhum crustal province. We have pointed out the problematic stratigraphic issues of the Singhbhum crustal province that deserve careful scrutiny in order to gain better insights into the mode of stratigraphic sequence building.

Beschreibung: The predictions from a numerical time-variant distributed groundwater model are used to assess the spatial and temporal impacts of groundwater abstraction for an unconfined and layered, moderate diffusivity aquifer; the West Midlands–Worfe Permo-Triassic Sandstone in the UK. These impacts have been determined by comparing a recent actual baseline predictive simulation with simulations where groundwater abstractions are switched off, including a ‘naturalized’ simulation. By reference to the historic simulation, the predictive model results are compared against observed groundwater levels. The predictive simulations demonstrate that observed groundwater levels could be an indicator of groundwater abstraction impacts on surface water flows where widespread stream disconnection has occurred due to high rates of abstraction. This relationship also depends on the aquifer hydraulic characteristics, the interaction between groundwater levels and the surface drainage network and other artificial flow influences. Abstraction impacts on groundwater levels are large for the West Midlands–Worfe aquifer, but can be obscured by the climatic recharge signal in observed groundwater level records. This is a consequence of the moderate diffusivity and the main groundwater abstraction development preceding systematic monitoring. The groundwater model can be used to identify which observation boreholes have negligible abstraction impacts; this may be valuable for identifying groundwater level records that are useful for climate change analysis.

Beschreibung: Evidence of past life found in the Vindhyan Supergroup exhibits extensive diversity and taxonomically unresolved morphological complexities indicating varied biological affinities, advanced life and macroevolutionary dynamics of evolving clades. The megascopic life of the supergroup documents possibly two macroevolutionary modes, demarcated as: (i) the Palaeo-Mesoproterozoic transitional period, which is represented by the fossil assemblages of the Semri and Rewa groups, and exhibits the domination of a diversified prokaryotic cyanobacterial community and moderately diversified megascopic life; (ii) the Neoproterozoic (Bhander groups, Uppermost Vindhyans), represented by the diversified and morphologically complex megascopic eukaryotes, and the emergence of multicellularity among plant and animal clades, viz. structures resembling bryophytes, sporophyte and Ediacara fauna. The overall Vindhyan fossils exhibit episodes of adaptive innovations and the emergence of complex morphologies in separate lineages of evolutionary history, resulting in extensive morphodiversity.The present assemblage can be represented by that of prokaryotes, eukaryotes, possibly a symbiotic association, a Jacutianema-like Neoproterozoic form, specimens possibly of vaucheriacean affinity, mesoscopic intermediate forms inferred as transitional forms of microscopic–megascopic evolution, discs with process-like structures, the emergence of animal life (Ediacaran fauna) and a number of other complex morphologies that have no parallels in time and space. Traditionally and conventionally, the age of the Vindhyan Supergroup is considered to be that of Palaeoproterozoic–Neoproterozoic.

Beschreibung: The Indian lithospheric plate assembles the history of geological events covering almost the entire history of our planet. The proto-Indian continent was an integral part of the Palaeoproterozoic supercontinent Columbia. Global mantle warming beneath this supercontinent triggered rising plumes that led to rifting and the emplacement of mafic dyke swarms and large igneous provinces in many of the major cratons of Peninsular India. Continued rifting and separation of crustal blocks led to the formation of thick passive margin successions. The opening of ocean basins and their eventual closure are recorded in the travelogue of oceanic plates from mid-ocean ridge to the trench in the form of ‘ocean plate stratigraphy’ in Proterozoic belts, including the association of dismembered ophiolites, pelagic sediments and continental margin sequences that were imbricated into accretionary belts such as those in the Aravalli–Delhi domain (Western India Suture), the Central India Tectonic Zone (Central India Suture) and the eastern margin of the East Dharwar Craton (Eastern India Suture). Recent U–Pb zircon chronology from ophiolitic rocks in the eastern margin of the Dharwar Craton shows ages spanning from 1.85 to 1.33 Ga suggesting a prolonged Wilson cycle of subduction–accretion processes before the final collisional event and the extrusion of high-grade metamorphic orogens. The extruded high pressure–temperature (P–T) metamorphic belts are often associated with mafic/ultramafic units with an abyssal signature. The available geophysical information from the Indian Palaeoproterozoic belts, particularly deep seismic reflection data, provides important clues on the architecture of these orogens and the subduction polarity. Whereas the Palaeoproterozoic convergent margins in the NW and SE sectors of the Indian peninsula were characterized by the westward subduction of oceanic plates, ocean closure along the Central India Tectonic Zone probably involved a double-sided subduction. The Wilson cycle traces a continuum from Palaeoproterozoic through Mesoproterozoic to Neoproterozoic in some of these belts, with a prolonged subduction–accretion history similar to the ongoing convergent margin processes in the western Pacific region. Peninsular India thus preserves a complete record from Pacific-type accretionary tectonics along the margins of the Columbia supercontinent to Himalayan-style collisional assembly within the Neoproterozoic Rodinia supercontinent.

Beschreibung: In the central and western part of India, the Neoproterozoic deposits are identified in the Vindhyan and Marwar Basins. The Vindhyan Basin consists of two sub-basins; one in the eastern part and the other in the western part. The basic problem with the Vindhyan Basin is the correlation of the eastern part with the western part, as the two areas show different stratigraphic successions and the outcrops in the eastern part are not traceable in the western part. In this paper, an attempt is made to suggest intrabasinal correlation within the Vindhyan Basin on the basis of stromatolites, carbon isotope data, microbial mats, fossils and lithology. The Marwar Supergroup is developed in the western Rajasthan and unconformably overlies the Malani Igneous Suite, which has previously been dated as 779–681 Ma. On the basis of the available fossil records, the Jodhpur Group has been assigned an Ediacaran age and the Precambrian–Cambrian boundary is suggested within the Bilara Group. As both the Maihar Sandstone of the eastern part of the Vindhyan Basin and the Jodhpur Sandstone of the Marwar Supergroup have been assigned an Ediacaran age, these have been correlated.

Beschreibung: Over time, Neoproterozoic rocks in Pakistan have intermittently attracted the interest of oil and gas exploration companies. However, despite these rocks having been penetrated by nearly 40 wells and being exposed in various parts of Pakistan, no serious efforts have yet been made to investigate their reservoir potential. Neoproterozoic rocks are exposed along the outer periphery of the Salt Range and Nagar Parker in Pakistan and in Rajasthan (India). Surface and subsurface data suggest a good correlation between outcrops in Rajasthan and wells in the Punjab Platform. However, the Neoproterozoic of the Punjab Platform seems to be somewhat different from that in Potwar, suggesting the existence of a kind of barrier or palaeo-high, separating the two basins. Proterozoic stromatolite found in a number of Himalayan sequences seems to be correlatable with similar facies encountered in other parts of the world, such as in the Abalog-1 and Yarba-1 wells in the Toudeni Basin in Mauritania and Mali, respectively. Glacial Pokhran boulder beds (representing snowball Earth) in the Hazara Basin, and reportedly in Pokran and Lawan across the border in India, also correlate with similar Neoproterozoic facies found in other parts of the world. Neoproterozoic offers a complete petroleum system. Regional data demand that the Neoproterozoic reservoir potential be re-evaluated, and a proper understanding of basinal configuration may play a vital role in future exploration success in this region.

Beschreibung: A dip histogram for intracontinental M〉5.5 reverse-slip ruptures reveals a trimodal distribution with a dominant Andersonian peak (fault dip, δ=30±5°) flanked by subsidiary clusters at δ=10±5° and 50±5°, and no dips greater than 60°. For a simple compressional regime (σv=σ3), the dominant peak is in accord with the reshear of optimally oriented faults with a friction coefficient of μs=0.6±0.2, implying frictional lock-up at δ=60±10° consistent with the observed upper dip bound. The low-dip cluster (δ=10±5°) is dominated by thrusting in the frontal Himalaya and may incorporate staircase thrust systems in cover sequences with deflections along bedding anisotropy. The cluster of moderate-to-steep reverse fault ruptures (δ=50±5°) is likely dominated by compressional inversion of inherited normal faults. In both circumstances, however, there appears to be competition between Andersonian thrusts in various stages of development and non-optimal failure planes dipping at either high or low angles. A delicate balance between levels of differential stress and fluid-pressure determines whether or not a poorly oriented thrust or reverse fault reactivates in preference to the development of new, favourably oriented Andersonian thrusts.

Beschreibung: Geological information on the Chotanagpur Granite Gneiss Complex (CGGC) has been reviewed with a view to: (a) identifying the different metamorphic episodes; (b) developing an event stratigraphy in the high-grade blocks; and (c) correlating the different metamorphic episodes with the globally extensive orogenic processes. Integrating the existing geological information, the geological evolution of the high-grade block of the CGGC has been divided into four stages associated with four distinct metamorphic events (MI-MIV). The earliest metamorphic event (MI) that is recorded in granulite enclaves in the regionally extensive felsic gneisses culminated in ultrahigh temperatures (〉900 °C at c. 5–8 kbar) at around 1.87 Ga. In the second stage, voluminous felsic magmas were intruded – the MI granulites – and were metamorphosed to form migmatitic felsic gneisses (MII) within about 1.66–1.55 Ga. The third stage witnessed intrusions of a suite of anorthosite and porphyritic granitoids (c. 1.55–1.51 Ga), followed by high-grade metamorphism (700±50 °C, 6.5±1 kbar, MIII) during approximately 1.2–0.93 Ga. The fourth stage (MIV) is marked by the intrusion of a suite of mafic dykes, followed by infiltration-driven metamorphism (600–750 °C at 7±1) during 0.87–0.78 Ga. The proposed metamorphic events have been correlated with the supercontinental cycles in the Proterozoic time.

Beschreibung: Amidst the Meso- to Neoproterozoic South Delhi Fold Belt (SDFB) of Rajasthan, India, a sheet-like body of megacrystic Anasagar Granite Gneiss (AGG) embedded in a supracrustal unit consisting of metapelites, quartzite and calc gneiss is exposed. Detailed analyses of mesoscopic and microscopic structures identify four phases of deformation. Lithological relationships coupled with U–Pb dates of zircon indicate that the protolith of the AGG was emplaced within the supracrustal unit during D1 folding at approximately 1.85 Ga. This event is significantly older than the age of volcanism in the SDFB (0.99 Ga) but probably synchronous with Aravalli Orogeny. Thrusts associated with the easterly-vergent D2 folds have a ramp–flat geometry and are refolded by coaxial D3 folds. The petrology of the metapelites indicates that porphyroblasts of staurolite and/or garnet were formed as a function of bulk-rock composition between D1 and D3 folding, at the time of the culmination of metamorphism (5.7±1.5 kbar, 560±50 °C). Combining the petrological and structural attributes, it is proposed that the AGG and its enveloping supracrustals might represent the basement of the Delhi Supergroup, which was folded, thrusted and domed up during the South Delhi Orogeny. The cause of the thermal perturbation that triggered the growth of the porphyroblasts in the metapelites is explored.

Beschreibung: The Upper Bhander Sandstone is dominantly composed of quartzarenites. The basal and top portions are sandstones, with the middle section comprising thinly bedded shales with interlayer silt and sandstone units. The sandstone units are composed of several varieties of quartz, feldspar, micas, rock fragments and heavy minerals. The Upper Bhander Sandstone was deposited in a transgressive phase and later modified by tidal processes and wave- and storm-dominated processes in a tide-influenced Barrier Beach Complex of the shallow marine environment. This study reveals that, during mechanical compaction, a rearrangement of grains took place and point and long contacts were formed. The early silica cementation and shallow burial resulted in high primary porosity. This phase was followed by chemical compaction and the replacement of silica cement by iron cement (Fe-cement) under the deep burial phase of these sandstones. Dissolution of Fe-cement and feldspars resulted in secondary porosity development. Quartz overgrowths are better developed on coarse- to medium-sized grains than on fine-sized grains. These observations suggest a progressive compaction, which initiated at the sediment–water interface and continued till deep burial diagenesis in a rapidly subsiding basin. The existing optical porosity of the Upper Bhander Sandstone is 4% and the minus cement porosity is 18%.

Beschreibung: The vast amount of new lithostratigraphic, chemostratigraphic and geochronologic data from the Huqf Supergroup (Sultanate of Oman) has established it as the Cryogenian (850–635 Ma) and Ediacaran (635–542 Ma) reference section for the Neoproterozoic of the Middle East Region. A direct litho- and chemostratigraphic comparison of the Huqf Supergroup of Oman with the supposed time-equivalent succession of the Marwar Supergroup in western Rajasthan (India) reveals remarkable affinities in facies evolution and chemostratigraphic signature through time. Ara Group equivalent strata are also found in the Salt Range Formation of Pakistan, which shows an almost identical repetition of evaporites and carbonates with six to seven basin refreshening–desiccation cycles, comparing well with the A0–A6 Ara Group stratigraphy of the South Oman Salt Basin. These similarities bring out a consistent picture of a cratonic setting for the Marwar Supergroup of West Rajasthan, changing into a more open marine setting towards Pakistan until Oman, suggesting an assembly of Oman–Pakistan and India ‘terrains’ prior to being accreted to the Arabian shield sometime after 650 Ma. From a petroleum exploration perspective, key success factors when pursuing the Late Neoproterozoic plays in the Salt Basins of India, Pakistan and Oman are source rock maturity, charge preservation and seal integrity.

Beschreibung: Tunnel valleys are elongated incisions that are commonly interpreted as being the result of erosional processes by subglacial meltwater occurring under continental ice sheets. The abundance, size and the primarily coarse-grained infill of these features have made tunnel valleys important hydrocarbon and groundwater reservoirs. Although numerous tunnel valleys have been described over the last century, their formation and infill remain poorly understood. This review summarizes and discusses the current knowledge of tunnel valleys, providing an overview of the observations around the world. Morphological aspects that separate tunnel valleys from other landforms are discussed, as well as the wide variety of sedimentary environments found to contribute to the infilling of these features. The depth of the incision and the character of ice retreat significantly determine the final infill architecture. The formational hypotheses proposed in the literature are assessed to test their wider applicability to all other tunnel valleys in order to find a generic model that helps in the prediction of the morphology and infilling of both Pleistocene and pre-Pleistocene age. A quasi-steady-state model, with small meltwater outbursts that erode tunnel valleys near the ice margin, seems compatible with most of the known valleys. Other proposed models require specific geographical or climatic conditions.

Beschreibung: An abundant well-preserved assemblage of annulated carbonaceous compressions and impressions has been recorded from the intra-cratonic argillaceous sedimentary sequence of the Bhima basin in south India. Impressions and carbonaceous compressions recorded in the Hulkal Formation belong to annulated forms similar to the previously reported Sinosabellidites huainanensis, Protoarenicola baiguashanensis and Pararenicola huaiyuanensis from China. This paper discusses the diversity, systematics, affinity, biostratigraphical potential and global significance of these remains. The previously proposed worm-like body fossil affinity for these organisms, based on similarity with the Chinese assemblage, has been reinterpreted as with pre-Ediacaran epibenthic organisms. Fresh investigations of the Indian assemblage of such specimens reveal their close proximity to the algal affinity. The occurrence of global marker events, such as phosphatization, the presence of complicated annulated carbonaceous remains in the Hulkal Formation and the absence of stromatolites in the carbonate sequences of the Bhima basin, collectively indicate a Neoproterozoic, possibly pre-Sturtian age for the Bhima Group.

Beschreibung: This paper proposes a model for glaciation in Oman during the late Palaeozoic ice age (LPIA) based on sedimentological and provenance analyses of the Late Carboniferous–Early Permian Al Khlata Formation, exposed in the Huqf, Oman. The results demonstrate a complex pattern of glaciation across Oman, not fully recognized in previous models. Striated glacial pavements provide evidence for two phases of ice advance: a phase of ice sheet advance towards the NE, and a second and probably younger phase where an ice centre localized on the Huqf High flowed towards the SW. The stratigraphy is constrained by previous palynological studies and is subdivided into three units, from oldest to youngest: ‘early’ AKP5, ‘late’ AKP5 and AKP5/P1. ‘Early’ AKP5 palaeogeography is characterized by ice-contact glacial lacustrine and deltaic sedimentary environments along the western margin of the Huqf High. Meltwater discharge flowed into the lake from ice margins located to the east, upon the Huqf High, recorded by progradational delta and fan complexes. ‘Late’ AKP5 palaeogeography is characterized by pro-glacial fluvial-deltaic outwash braidplains that record high-magnitude meltwater discharge from an ice margin located to the SW of the study area. The youngest undifferentiated AKP5/P1 palaeogeography is characterized by re-establishment of ice-contact glaciolacustrine conditions.

Beschreibung: The architecture, distribution and development of channelized sandstone bodies are described from Late Ordovician paraglacial successions of the Tassili N'Ajjer (SE Algeria and SW Libya) based on satellite images and field data (sedimentary logs, photomosaics). Sandstone bodies have a ribbon-like form at outcrop (often referred to as ‘cordons’ in the literature). They typify a fluvioglacial outwash plain deposited between a continental ice front and a marine delta-front zone. Channelized sandstone bodies are straight to sinuous, with widths (W) in the 60–600 m range, thicknesses (T) in the 5–30 m range and they have a mean W/T ratio of 16.5. They develop within an aggradational–progradational sand-dominated deltaic topset succession including at its distal end a terminal distributary channel and mouth-bar environments. The architecture of channel bodies and the related depositional facies, which includes climbing-dune cross-stratification, indicates that channelized sandstone bodies represent plugs of isolated channels related to high-magnitude flood events (glacier outbursts). These plugs form fossilized networks of both braided channels and interlaced anastomosed channels, offering snapshots of an outburst-related unconfined proglacial outwash braidplain constituted by the amalgamation of adjacent, elongated outwash fans.

Beschreibung: Evidence is presented for an Early Pleistocene grounded ice sheet in the Central North Sea (CNS). Dated basal Quaternary deposits from UK well 30/13-2 Josephine coincide with the lowest iceberg ploughmarked horizon in a southern CNS depocentre. This horizon has been traced northwards into the central CNS where it is identified as the Crenulate reflection, which exhibits a series of deep, channel-like features, interpreted as subglacial meltwater channels. Further north, a seismic reflection at the same level is characterized by megascale lineations that are interpreted to be the result of erosion, deposition and deformation of sediment beneath an advancing ice sheet. An overlying seismic reflection is characterized by a well-developed channel system that is thought to have drained the retreating ice sheet prior to a post-glacial marine transgression. A southern CNS Early Pleistocene depocentre is shown to have become inactive sometime in the Early to Middle Pleistocene and was replaced by a developing depocentre in the central and northern CNS that remained active into the Late Pleistocene. Evidence for an Elsterian or older grounded ice sheet in UK Continental Shelf Quad 22 is presented in the form of glaciotectonic thrust features.

Beschreibung: The Late Palaeozoic glaciation was the longest of the Phanerozoic era. It is recorded in numerous Gondwanan basins, with some, such as the Chaco Basin, having a high petroleum potential. In this basin, the quality of the available seismic, well and outcrop data permits us to characterize the Late Palaeozoic glacial record. Palaeovalleys that are c. 500 m deep and c. 7 km wide have been analysed here. Focusing on the glaciogenic Carboniferous deposits, seismic data with well ties and outcrop analogues provide new sedimentological insights. The palaeovalley infill is imaged as a chaotic seismic facies overlain by an aggrading–prograding prism, interpreted as tillites covered by a fluvio-deltaic system. Tillites form both under the ice and during rapid ice recession, whereas fluvio-deltaic systems can only originate from a stable ice margin and last until the ice sheets withdraw inland. These two depositional modes are repeated several times, generating a progressive burial of the Carboniferous palaeovalleys. This succession of erosions and fills records major glacial stages, including a series of glacial and interglacial phases from the Late Devonian to the Early Permian. Depicting the Late Palaeozoic glacial history of the Chaco Basin seems crucial for the localization of potential good reservoirs.

Beschreibung: Ordovician proglacial deposits form gas reservoirs in the In Amenas field, Illizi Basin, Algeria. Depositional models were developed to understand the context and disposition of the main reservoirs through an evaluation of core and analogous outcrops from the Tassili N'Ajjer.Tunnel valleys initially accumulated sandstones with tractional structures. Subsequent failures of subaqueous grounding line sediment deposited proglacial debrites comprising poorly sorted argillaceous sandstone with granules. These were interbedded with high-density turbidity sandstones; their fine grain size indicates they were dynamically disconnected from the lithologically varied debrites. A lobate geometry has been defined for one subsurface composite turbidite.Periodic catastrophic outflows, possibly evacuating subglacial lakes, incised the network of subglacial tunnels and in the process delivered sand to the turbidite outwashes. Bedforms indicate high-energy, transcritical to supercritical outflows that were stable for extended periods. During ice retreat, a period of ice margin stability may have occurred due to grounding over the In Amenas granitic palaeohighs. Outwash fan apices were located along this grounding line with feeder channels developing where the substrate was more easily eroded such as between the palaeohighs. Following further ice retreat, deposition evolved to variably sinuous channels and thence to pelagic fines with dropstones.

Beschreibung: The Golfo San Jorge Basin is one of the most important hydrocarbon-producing basins in Argentina. A study of magnetic properties performed on drill cutting from an oil well drilled in this basin was carried out. The cutting samples, taken from an interval of about 400 m thickness, correspond to the upper units of the Pozo D-129 Formation, the main source rock of the basin. Magnetic susceptibility measurements were made and rock-magnetism studies were conducted. Concentration indices of the different magnetic species determined were calculated based on isothermal remanent magnetization acquisition curves. A correlation analysis among magnetic properties, hydrocarbon content and well logs (sonic, neutron, density, induction, resistivity and photoelectric factor) was performed. Several kinds of significant correlations were found: a positive correlation between susceptibility and relative hydrocarbon content; a positive correlation between magnetic properties and porosities (especially good with the neutron log porosity); and a negative correlation between the concentration indices of some magnetic species (magnetite and pyrrhotite) and resistivity. Pyrrhotite could be directly related to the presence or migration of hydrocarbons through the porous units.The qualitative correlations between magnetic data and key petrophysical parameters such as porosity, along with the association of magnetic mineralogy to hydrocarbon presence or migration, suggest the potential usefulness of these techniques for subsurface exploration.

Beschreibung: This paper analyses the spatial pattern of three tropical storm migratory behaviour parameters – track sinuosity, minimum pressure and duration of intense typhoons. The best-track data of the western North Pacific basin archived by the Regional Specialized Meteorological Center in Tokyo were used. The local Getis–Ord Gi*(d) statistic (where d is distance) was employed in a geographical information system (GIS) environment to identify clusters of hot spots and cold spots of the three parameters. The analysis of storm-track sinuosity identified one dominant hot-spot cluster of sinuously tracking storms far from the continental margins of the North Pacific Ocean, with three small cold-spot clusters of straight-tracking storms relatively close to mainland SE Asia. The analysis of the second and third parameters revealed extensive overlap between the cluster of very intense typhoons (i.e. hot-spot cluster of minimum pressure, mean 926 hPa) and the cluster of long-duration typhoons (i.e. hot-spot cluster of duration at typhoon intensity, mean 5.4 days). The findings suggest that the Philippines and the Northern Marianas Islands are vulnerable to strike by both longer-lived and extremely violent typhoons. Overall, the technique highlights the strong potential for statistical clustering analysis to visualize and understand geospatial patterns in typhoon meteorological characteristics.

Beschreibung: A combination of computational power, dynamic graphics and geographical information system (GIS) packages creates a powerful platform for advanced visualization tools to explore complex geographical phenomena in an interactive computer environment – known as geovisualization. Geovisualization is a relatively new computer-based approach that refers to a set of methods and techniques to support geospatial data analysis through the use of four-dimensional (4D), multi-variable and interactive visualization. In this paper, we illustrate and discuss the value of several spatialization techniques that are used to perform analysis of spatial structures of climatic and meteorological elements, especially through the geovisualization of characteristics and behaviour of tropical cyclones in the South Pacific Ocean. Preliminary findings are encouraging, allowing patterns and dependencies between chosen cyclone features to be identified, in turn indicating the enormous potential of geovisualization for analysing multi-variate spatial attributes within large tropical cyclone datasets.

Beschreibung: This book, generated under the auspices of the Geological Society of London's History of Geology and Hydrogeological Groups, contains 20 papers from authors in the UK, USA, Germany and Austria. Historically, it gives examples of the influence of groundwater on battlefield tactics and fortress construction; describes how groundwater was developed for water supply and overcome as an obstacle to military engineering and cross-country vehicular movement by both sides in World Wars I and II; and culminates with examples of the application of hydrogeology to site boreholes in recent conflicts, notably in Afghanistan. Examples of current research described include hydrological model development; the impact of variations in soil moisture on explosive threat detection and cross-country vehicle mobility; contamination arising from defence sites and its remediation; privatization of water supplies; and the equitable allocation of resources derived from an international transboundary aquifer.

Beschreibung: The US Army has compelling needs for making hydrological forecasts. These range from tactical predictions of water levels and soil moisture, to strategic protection of both Army and civilian assets and environmental resources. This paper discusses the history of hydrological model development by the US Army Corps of Engineers (USACE) as influenced by changes in needs and technologies. It concludes with a description of the Gridded Surface/Subsurface Hydrologic Analysis (GSSHA™) model, a two-dimensional, structured-grid, physics-based hydrological, hydrodynamic, sediment and nutrient/contaminant transport model, developed over the past two decades, that is currently used by the USACE. The surface hydrology of the USA has been divided by the US Geological Survey into 21 major geographic domains that contain either the drainage area of a major river or the combined drainage areas of a series of rivers of similar character developed in one geographic province. Eighteen of the regions occupy the land area of the conterminous USA. Alaska, the Hawaiian Islands and Puerto Rico are separate domains. This approach provides a framework for the hydrological modelling discussed in this paper for sites within six of these regions. That the physics-based GSSHA modelling capability has so far been applied with success gives confidence in its more widespread application.