ALBERT

Description: The James Ross Basin, at the northern tip of the Antarctic Peninsula, provides the thickest and best-exposed onshore Cretaceous and Early Tertiary sedimentary succession in Antarctica. When compared with other onshore sections, it is clear that the area has a much broader significance as a key reference section for the Cretaceous and Early Tertiary throughout the Southern Hemisphere. The sedimentary record exposed within the basin also provides an unrivalled opportunity to unlock the record of climate change and biotic response within a high-palaeolatitude setting. James Ross Island was first visited during the heroic age of polar exploration at the start of the 20th century. Swedish geologist Otto Nordenskjold sailed into the region in 1901 in his ship Antarctic, captained by explorer and sealer Carl Larsen. Plans to spend a year in the region for scientific exploration went disastrously wrong when his ship sank near Paulet Island, forcing Nordenskjold to spend over 2 years in a small hut on Snow Hill Island. Members of his ship-wrecked party survived in horrific conditions, with only penguins for food and small stone huts for shelter at Hope Bay, at the tip of Trinity Peninsula, and also on Paulet Island. Nordenskjold's enforced stay in the area was, however, not unprofitable. In 1902 he and his five companions made trips over the sea ice to Seymour Island, where they made the first important fossil discoveries, including the bones of giant penguins (now known to be from the Eocene La Meseta Formation). This was well before Scott's ... This 250-word extract was created in the absence of an abstract.

Description: Organic-rich sediments were deposited in the deeper sectors of the Neuquen Basin during the latest Jurassic and the Early Cretaceous. This paper presents the results of a detailed examination of these deposits in the northern-most extension of the basin, in the Mendoza Province, and explores their wider significance for palaeo-oxygenation studies. The Tithonian--Berriasian Vaca Muerta Formation, the primary source rock for the Neuquen Basin, comprises bituminous shales and interbedded limestones deposited during a major transgression. In the Valanginian, the beginning of a regressive phase enabled the development of shallow-marine carbonates to form the base of the Chachao Formation, which eventually led to extensive biohermal carbonates of the uppermost Chachao Formation. Along the length of the narrow N-S-trending Mendoza Shelf of the Neuquen Basin both units are well exposed, permitting detailed study of the stratigraphy, sedimentology, ichnology and palaeoecology. The analysis of the Tithonian--Valanginian succession in the Salado river valley shows that carbonate production increased up-section. Faunal associations are mostly limited to poorly diverse epibenthos and pseudoplankton in the lower part of the section (Vaca Muerta Formation), with increased diversity in the lower Chachao section, including shallow and deeper infaunal bivalves. A background level of laminated shales to Chondrites bioturbation is typical of anoxic--suboxic conditions. Micritic limestones and carbonate sandstones throughout the section commonly show the development of Thalassinoides suevicus. Relative oxygenation curves based on trace fossils and body fossils were developed and compared. There was a primary substrate control on trace fossil diversity and occurrence, with a primary oxygenation signal provided by body fossil evidence. Interpretation of the palaeo-oxygenation on the basis of trace fossil taxa alone, however, would lead to inaccurate results. This study, therefore, demonstrates the importance of integrated trace and body fossil analysis in the fuller understanding of black shales.

Description: The extensive Cretaceous sedimentary sequence exposed within the James Ross Basin, Antarctica, is critical for regional stratigraphic correlations in the Southern Hemisphere, and also for our understanding of the radiation and extinction of a range of taxonomic groups. However, the nature and definition of Cenomanian-Turonian strata on the NW margins of James Ross Island has previously been difficult, due both to marked lateral facies changes and to stratigraphical discontinuities within the extensive Whisky Bay Formation. Facies variation and local unconformities were the result of fault-controlled deep-marine sedimentation along the basin margin. In this study the Albian-Cenomanian boundary is defined for the first time in the upper levels of the Lewis Hill Member of the Whisky Bay Formation. However, there is a Cenomanian-late Turonian unconformity between the Lewis HIll and Brandy Bay members of the Whisky Bay Formation. Equivalent lithostratigraphical units exposed further to the SW on James Ross Island appear to be more complete with the early Cenomanian-late Turonian interval represented by the upper parts of the Tumbledown Cliffs and the lower part of the Rum Cove members of the Whisky Bay Formation. The Turonian-Coniacian boundary is provisionally placed at the junction between the Whisky Bay and Hidden Lake formations. The revised stratigraphic ages for this section show that the Late Cretaceous radiations of a number of major plant and animal groups can be traced back to at least the Turonian stage. This raises the possibility that their dissemination might be linked to the global Cretaceous thermal maximum.

Description: Geological trace evidence including, for example, soil, sand and rock dust has been examined using a wide range of analytical techniques. Whilst such materials are common in rural locations, in urban areas, such geological materials are often perceived to be restricted to parks, recreational areas, gardens and waste ground. However, both geological materials and the wide range of analytical methods used to characterize them are much more applicable to the whole urban environment than is generally realized, with the main differences being the types and amounts of sample analysed and the methods adopted. The range of geological applications can be summarized as those deployed at the broad (decimetres–kilometres) to small (millimetres–decimetres) scale. The broad spatial variation in soil, roadway, water, buildings materials, and wind- or water-borne particles can be contrasted with the variation in urban materials from dwellings to streets or gardens and parks, along with the micro-spatial and stratigraphical variation in each. In addition, geological principles and techniques that have not been used before can be applied to urban materials to provide comparisons of material that were not previously achievable, or to add a further proxy to established methods. The latter point is demonstrated with a case study using X-ray diffraction and QEMSCAN ® of a criminal case where building plaster with peculiar qualities could be compared between a suspect's vehicle and plaster present along the escape route from a murder scene.

Description: Many subdisciplines within the Earth Sciences make use of either geophysical instruments to investigate the subsurface environment or use analytical methods to determine the origin, or provenance, of geological materials. These same instruments and analytical methods can be used either directly, or adapted to suit, the acquisition of data that pertain to a wide range of forensic science investigations. Such approaches, as discussed below, are generally not new but, in recent years, there has been a significant resurgence globally in the application of geological and geophysical methods to aid forensic investigations. Traditionally, such methods were used in forensic investigations related to serious criminal cases such as terrorism, murder, abduction and serious sexual assaults, and to a lesser extent in the investigation of cases of fraud and theft. But with increasing concern into the environmental impact of human activity, with the release of contaminants into the atmosphere, hydrosphere and lithosphere, and their potential uptake into the biosphere, there has been an increased amount of environmental legislation. In turn, there has commonly been an increase in the costs associated with the legal discharge or disposal of wastes. Consequently, it is unsurprising that the illegal discharge and disposal of wastes has also increased. Identifying the distribution, impact and source of such waste materials can, in part, be addressed through the application of geological techniques, in much the same way as used traditionally, for example, in the investigation of murder cases. The diversification of the use of geological techniques into the investigation of environmental crime will, potentially, significantly increase the range of investigations in which geologists may be asked to assist but will also lead to a new array of research questions to be addressed, hence the need for this Special Publication. In this short introduction, the aim is to place the current work into its broad historical context and summarize the key findings from the papers presented within this volume. The papers within this Special Publication were presented at two separate conferences in 2010: the Third International Soil Forensics Conference held at Long Beach California USA and organized by the SFI Group; and a conference on Environmental and Criminal Forensics, organized by the Forensic Geoscience Group of the Geological Society of London, and held at Burlington House, London, in December 2010.

Description: Trinitite is the glass formed during the first atomic bomb test near Socorro, New Mexico, on July 16, 1945. The protolith for the glass is arkosic sand. The majority of the glass is bottle green in color, but a red variety is found in the northern quadrant of the test site. Glass beads and dumbbells, similar in morphology to micro-tektites, are also found at the Trinity site. The original description of this material, which appeared in American Mineralogist in 1948, noted the presence of two glasses with distinctly different indices of refraction (n = 1.46 and 1.51–1.54). Scanning electron microscopy (SEM) and Quantitative Evaluation of Minerals by SCANning electron microscopy (QEMSCAN) analysis is used to investigate the chemical composition and fine-scale structure of the glass. The glass is heterogeneous at the tens of micrometer scale with discrete layers of glass showing flow-like structures. The low index of refraction glass is essentially SiO 2 (high-Si glass), but the higher index of refraction glass (low-Si glass) shows a range of chemical compositions. Embedded in the glass are partially melted quartz (α-quartz as determined by X-ray diffraction) and feldspar grains. The red trinitite consists of the same two glass components along with additional Cu-rich, Fe-rich, and Pb-rich silicate glasses. Metallic globules are common in the red trinitite In terms of viscosity, the high-Si and low-Si glasses differ by several orders of magnitude, and there is minimal mixing between the two glasses. QEMSCAN analysis reveals that there are several chemical subgroups (that can be characterized as simple mixtures of melted mineral components) within the low-Si glasses, and there is limited mixing between these glass subgroups. The red trinitite contains regions of Fe-rich glass, which show sharp contact with surrounding Fe-poor glass. Both the textural and chemical data suggest that these two glasses existed as immiscible liquids. The metallic droplets in the red trinitite, which consist of variable amounts of Cu, Pb, and Fe, show textural evidence of unmixing. These metals are largely derived from anthropogenic sources—Cu wire, Pb bricks, and the steel tower and bomb casing. The combination of mineralogical and chemical data indicate that temperatures on the order of 1600 °C and pressures of at least 8 GPa were reached during the atomic detonation and that there was a reducing environment during cooling, as evidenced by the presence of native metals, metal sulfides, and a low-Fe 3+ /Fe 2+ ratio. Independent estimates of maximum temperature during the detonation are on the order of 8000 K, far higher than suggested by the mineral data. This discrepancy is probably due to the very short duration of the event. In all respects, the trinitite glasses are similar to tektites and fulgurites, and by analogy one conclusion is that temperature estimates based on mineralogical observations for these materials also underestimate the maximum temperatures.