ALBERT

Description / Table of Contents: PREFACE Following the economical and social development of the local communities, mountain regions of temperate climates are increasingly becoming the site of valuable infrastructures and important urban and industrial settlements. As the catastrophic events of last years in the European Alps have clearly shown, the vulnerability of these territories has correspondingly increased, in terms of both property damage and losses of human life. Until recently, the hydraulic scientific community has paid little attention to mountain watersheds, except perhaps during the period if the hydropower development. Nevertheless attention was then focused on problems and methodologies somewhat different from the issues of actual environmental concern. More recently, however, hydraulic engineers have joined their colleagues from forest and rural engineering, who have traditionally dealt with erosion control in mountain areas, to bring in their own methodology, already experienced in lowland rivers. At the same time, academic people focused an interest in some phenomena, like massive transport, which is typical of mountain environment. To bring together all these contributions and to make the state of the art of the mountain river science (oropotamology) and technology, an International Workshop was called at the University of Trent (Italy), on October 1989, under the sponsorship of Fluvial Hydraulic Section of the IAHR. Three main topics have been recognized as particularly relevant from the point of view of both research and professivnal people: a) Hydrodynamics of steep channels and local scale process; b) Sediment movement and sediment training, with special emphasis on massive transport; c) Particular features of sediment transport related to non-uniform grain-size. However, as it is the case in these circumstances, the contest of several contributions often spread over more than one topic. In the following Introduction to papers, the three topics were split into 11 Sections, each one devoted to a more particular aspect recurrently addressed during the discussion. The same paper, thus, may be mentioned in different Sections of the Introduction.

Description / Table of Contents: Introduction / Pages 1-32 --- Interpretation using nomograms / Pages 33-47 --- Linear parameters / Pages 49-114 --- Non-linear parameters / Pages 115-173 --- Maximum likelihood and maximum entropy / Pages 175-193 --- Analytic inversion / Pages 195-211 --- Advanced inversion methods / Pages 213-227 --- Error analysis / Pages 229-243 --- Parallel computation in modelling and inversion / Pages 245-255

Description / Table of Contents: PREFACE This book represents the first attempt in three decades to marshall out available information on the regional geology of Africa for advanced undergraduates and beginning graduate students. Geologic education in African universities is severely hampered by the lack of a textbook on African regional geology. This situation is greatly exacerbated by the inability of most African universities to purchase reference books and maintain journal subscriptions. Besides, geologic information about Africa is so widely dispersed that a balanced and comprehensive course content on Africa is beyond the routine preparation of lecture notes by university teachers. Since geology is a universal subject and Africa is one of the largest landmasses on Earth with one of the longest continuous records of Earth history, there is no doubt that geologic education in other parts of the world will benefit from a comprehensive presentation of African geologic case histories. The scope of this text also addresses the need of the professional geologist, who may require some general or background information about an unfamiliar African geologic region or age interval. Africa occupies a central position in the world's mineral raw materials trade. Because of its enormous extent and great geologic age, the diversity and size of Africa's mineral endowment is unparalleled. Africa is the leading source of gold, diamond, uranium, and dominates the world's supply of strategic minerals such as chromium, manganese, cobalt, and platinum. Consequently, African nations from Algeria to Zimbabwe depend solely on mineral exports for economic survival. The geologic factors which govern economic mineral deposits are stressed in this text. The geological history of Africa spans 3.8 billion years, a record that is unique both in duration and continuity. Few other parts of our planet match the plethora of geologic phenomena and processes that are displayed in the African continent. From the various stages of crustal evolution decipherable from the Archean of southern Africa, through the plate tectonics scenarios in the ubiquitous Late Proterozoic-Early Paleozoic Pan-African mobile belts and in the Hercynian and Alpine orogenies of northwest Africa, to the East African Rift Valley, Africa is replete with excellent examples and problems for a course on regional tectonics. Teachers of igneous and metamorphic petrology can hardly ignore Africa's anorogenic magmatism (e.g.. layered ultramafic intrusives such as the Great Dyke and the Bushveld Complex; the Tete gabbro-anorthosite pluton; alkaline complexes; basaltic volcanism), or tantalizing highgrade metamorphic terranes such as the Limpopo belt, the Namaqua mobile belt, and the Mozambique belt. From the extensive Precambrian supracrustal sequences throughout the continent with enormous thicknesses of sedimentary rocks that have hardly been deformed or metamorphosed, to the stratigraphic evolution of Africa's present-day passive continental margin, there is a complete spectrum of facies models upon which to base a course on basin analysis and stratigraphy. To maintain its integrity a course on historical geology anywhere in the world must address the theory of Continental Drift beyond invoking past continuities between West Africa and South America. Past connections between West Africa and eastern North America must equally be explored, so also connections between northeast Africa and Arabia, and the paleogeography of southern Gondwana where Africa occupied centre stage. The Precambrian fossil record, the transitions from reptiles to the earliest mammals and dinosaurs, and the evolution of Man are among Africa's unique contributions to the history of life and the story of organic evolution. Although it lies today in the tropics Africa was the theatre of the Earth's most-spectacular glaciations. Even after the scene of continental glaciation had shifted to the northern continents only lately during the Pleistocene, Africa still witnessed spectacular climatic fluctuations during the Quaternary. Certainly students of archeology and paleoanthropology cannot overlook the Quaternary paleoenvironmental record of the Olduvai Gorge in Tanzania, the Lake Turkana basin in Kenya, the Nile valley, the Sahara, and southern Africa. But since African examples have already been cited in standard geologic textbook, I have often been asked why it has become necessary to revive the idea of a full-length textbook on African geology, 30 years after this idea was abandoned by the geologic community. My simple answer, as already stated, is that the wealth of available geologic information about Africa is so enormous and fascinating, but so diffuse, that an attempt must be made to assemble and pass on this knowledge.

Description / Table of Contents: PREFACE Sedimentation as a Three-Component System describes the most common styles of deposition in marine environments as they relate to sediment composition. Three components, organic matter, carbonate, and siliciclastic sediment, may settle concurrently, but at different rates, intermixing on the sea floor to form a particular sediment composition. A change in the flux of one component is capable of relatively diluting or concentrating the other two components, which can be expressed in the characteristic ratio of organic carbon to carbonate in the resulting sediment. The basic concept of this book is to address organic carbon-carbonate associations in terms of depositional inputs and time spans. In addition, the three-component system describes organic carbon changes related to major facies transitions. Examples include models of the genesis of carbonaceous sediments, with their various laminated to bioturbated lithotypes, and numerical organic carbon prediction. I hope that this book will encourage stimulating discussions and promote a new approach to quantitative stratigraphy...

Description / Table of Contents: The 1957 great Aleutian earthquake.- The rupture process and tectonic implications of the great 1964 Prince William Sound earthquake.- Coseismic slip in the 1964 Prince William Sound earthquake A new geodetic inversion.- Seismicity trends and potential for large earthquakes in the Alaska-Aleutian region.- Rupture process of large earthquakes in the northern Mexico subduction zone.- Global variability in subduction thrust zone-forearc systems.- Large thrust earthquakes and volcanic eruptions.

Description / Table of Contents: E. P. Wright: The hydrogeology of crystalline basement aquifers in Africa / Geological Society, London, Special Publications, 66:1-27, doi:10.1144/GSL.SP.1992.066.01.01 --- R. M. Key: An introduction to the crystalline basement of Africa / Geological Society, London, Special Publications, 66:29-57, doi:10.1144/GSL.SP.1992.066.01.02 --- F. A. K. Farquharson and A. Bullock: The hydrology of basement complex regions of Africa with particular reference to southern Africa / Geological Society, London, Special Publications, 66:59-76, doi:10.1144/GSL.SP.1992.066.01.03 --- D. Greenbaum: Structural influences on the occurrence of groundwater in SE Zimbabwe / Geological Society, London, Special Publications, 66:77-85, doi:10.1144/GSL.SP.1992.066.01.04 --- Eduard Boeckh: An exploration strategy for higher-yield boreholes in the West African crystalline basement / Geological Society, London, Special Publications, 66:87-100, doi:10.1144/GSL.SP.1992.066.01.05 --- M. J. McFarlane: Groundwater movement and water chemistry associated with weathering profiles of the African surface in parts of Malawi / Geological Society, London, Special Publications, 66:101-129, doi:10.1144/GSL.SP.1992.066.01.06 --- M. J. McFarlane, P. J. Chilton, and M. A. Lewis: Geomorphological controls on borehole yields: a statistical study in an area of basement rocks in central Malawi / Geological Society, London, Special Publications, 66:131-154, doi:10.1144/GSL.SP.1992.066.01.07 --- J. R. T. Hazell, C. R. Cratchley, and C. R. C. Jones: The hydrogeology of crystalline aquifers in northern Nigeria and geophysical techniques used in their exploration / Geological Society, London, Special Publications, 66:155-182, doi:10.1144/GSL.SP.1992.066.01.08 --- R. D. Barker, C. C. White, and J. F. T. Houston: Borehole siting in an African accelerated drought relief project / Geological Society, London, Special Publications, 66:183-201, doi:10.1144/GSL.SP.1992.066.01.09 --- R. M. Carruthers and I. F. Smith: The use of ground electrical survey methods for siting water-supply boreholes in shallow crystalline basement terrains / Geological Society, London, Special Publications, 66:203-220, doi:10.1144/GSL.SP.1992.066.01.10 --- R. Herbert, J. A. Barker, and R. Kitching: New approaches to pumping test interpretation for dug wells constructed on hard rock aquifers / Geological Society, London, Special Publications, 66:221-242, doi:10.1144/GSL.SP.1992.066.01.11 --- John Houston: Rural water supplies: comparative case histories from Nigeria and Zimbabwe / Geological Society, London, Special Publications, 66:243-257, doi:10.1144/GSL.SP.1992.066.01.12

Description / Table of Contents: Magma Generation and Break-Up Processes --- R. S. White: Magmatism during and after continental break-up / Geological Society, London, Special Publications, 68:1-16, doi:10.1144/GSL.SP.1992.068.01.01 --- Millard F. Coffin and Olav Eldholm: Volcanism and continental break-up: a global compilation of large igneous provinces / Geological Society, London, Special Publications, 68:17-30, doi:10.1144/GSL.SP.1992.068.01.02 --- Martin A. Menzies: The lower lithosphere as a major source for continental flood basalts: a re-appraisal / Geological Society, London, Special Publications, 68:31-39, doi:10.1144/GSL.SP.1992.068.01.03 --- A. D. Saunders, M. Storey, R. W. Kent, and M. J. Norry: Consequences of plume-lithosphere interactions / Geological Society, London, Special Publications, 68:41-60, doi:10.1144/GSL.SP.1992.068.01.04 --- S. A. Gibson, R. N. Thompson, P. T. Leat, A. P. Dickin, M. A. Morrison, G. L. Hendry, and J. G. Mitchell: Asthenosphere-derived magmatism in the Rio Grande rift, western USA: implications for continental break-up / Geological Society, London, Special Publications, 68:61-89, doi:10.1144/GSL.SP.1992.068.01.05 --- D. K. Bailey: Episodic alkaline igneous activity across Africa: implications for the causes of continental break-up / Geological Society, London, Special Publications, 68:91-98, doi:10.1144/GSL.SP.1992.068.01.06 --- Don L. Anderson, Yu-Shen Zhang, and Toshiro Tanimoto: Plume heads, continental lithosphere, flood basalts and tomography / Geological Society, London, Special Publications, 68:99-124, doi:10.1144/GSL.SP.1992.068.01.07 --- Martin H. P. Bott: The stress regime associated with continental break-up / Geological Society, London, Special Publications, 68:125-136, doi:10.1144/GSL.SP.1992.068.01.08 --- Early Stages of Gondwana Break-Up --- K. G. Cox: Karoo igneous activity, and the early stages of the break-up of Gondwanaland / Geological Society, London, Special Publications, 68:137-148, doi:10.1144/GSL.SP.1992.068.01.09 --- B. C. Storey, T. Alabaster, M. J. Hole, R. J. Pankhurst, and H. E. Wever: Role of subduction-plate boundary forces during the initial stages of Gondwana break-up: evidence from the proto-Pacific margin of Antarctica / Geological Society, London, Special Publications, 68:149-163, doi:10.1144/GSL.SP.1992.068.01.10 --- David H. Elliot: Jurassic magmatism and tectonism associated with Gondwanaland break-up: an Antarctic perspective / Geological Society, London, Special Publications, 68:165-184, doi:10.1144/GSL.SP.1992.068.01.11 --- T. S. Brewer, J. M. Hergt, C. J. Hawkesworth, D. Rex, and B. C. Storey: Coats Land dolerites and the generation of Antarctic continental flood basalts / Geological Society, London, Special Publications, 68:185-208, doi:10.1144/GSL.SP.1992.068.01.12 --- C. W. Rapela and R. J. Pankhurst: The granites of northern Patagonia and the Gastre Fault System in relation to the break-up of Gondwana / Geological Society, London, Special Publications, 68:209-220, doi:10.1144/GSL.SP.1992.068.01.13 --- South Atlantic Opening --- C. J. Hawkesworth, K. Gallagher, S. Kelley, M. Mantovani, D. W. Peate, M. Regelous, and N. W. Rogers: Paraná magmatism and the opening of the South Atlantic / Geological Society, London, Special Publications, 68:221-240, doi:10.1144/GSL.SP.1992.068.01.14 --- Marjorie Wilson: Magmatism and continental rifting during the opening of the South Atlantic Ocean: a consequence of Lower Cretaceous super-plume activity? / Geological Society, London, Special Publications, 68:241-255, doi:10.1144/GSL.SP.1992.068.01.15 --- M. P. R. Light, M. P. Maslanyj, and N. L. Banks: New geophysical evidence for extensional tectonics on the divergent margin offshore Namibia / Geological Society, London, Special Publications, 68:257-270, doi:10.1144/GSL.SP.1992.068.01.16 --- Northwest Indian Ocean and Gulf of Aden --- C. W. Devey and W. E. Stephens: Deccan-related magmatism west of the Seychelles-India rift / Geological Society, London, Special Publications, 68:271-291, doi:10.1144/GSL.SP.1992.068.01.17 --- M. A. Menzies, J. Baker, D. Bosence, C. Dart, I. Davison, A. Hurford, M. Al’Kadasi, K. McClay, G. Nichols, A. Al’Subbary, and A. Yelland: The timing of magmatism, uplift and crustal extension: preliminary observations from Yemen / Geological Society, London, Special Publications, 68:293-304, doi:10.1144/GSL.SP.1992.068.01.18 --- North Atlantic Opening --- Jakob Skogseid, Tom Pedersen, Olav Eldholm, and Bjørn T. Larsen: Tectonism and magmatism during NE Atlantic continental break-up: the Vøring Margin / Geological Society, London, Special Publications, 68:305-320, doi:10.1144/GSL.SP.1992.068.01.19 --- Lotte M. Larsen, Asger K. Pedersen, Gunver K. Pedersen, and Stefan Piasecki: Timing and duration of Early Tertiary volcanism in the North Atlantic: new evidence from West Greenland / Geological Society, London, Special Publications, 68:321-333, doi:10.1144/GSL.SP.1992.068.01.20 --- R. C. O. Gill, A. K. Pedersen, and J. G. Larsen: Tertiary picrites in West Greenland: melting at the periphery of a plume? / Geological Society, London, Special Publications, 68:335-348, doi:10.1144/GSL.SP.1992.068.01.21 --- Paul Martin Holm, Niels Hald, and Troels F. D. Nielsen: Contrasts in composition and evolution of Tertiary CFBs between West and East Greenland and their relations to the establishment of the Icelandic mantle plume / Geological Society, London, Special Publications, 68:349-362, doi:10.1144/GSL.SP.1992.068.01.22 --- H. C. Larsen and C. Marcussen: Sill-intrusion, flood basalt emplacement and deep crustal structure of the Scoresby Sund region, East Greenland / Geological Society, London, Special Publications, 68:365-386, doi:10.1144/GSL.SP.1992.068.01.23 --- Aidan M. Joy: Right place, wrong time: anomalous post-rift subsidence in sedimentary basins around the North Atlantic Ocean / Geological Society, London, Special Publications, 68:387-393, doi:10.1144/GSL.SP.1992.068.01.24

Description / Table of Contents: A. Hurst, C. M. Griffiths, and P. F. Worthington: Introduction / Geological Society, London, Special Publications, 65:vii-viii, doi:10.1144/GSL.SP.1992.065.01.01 --- Sedimentology and Stratigraphic Correlation --- Roger M. Slatt, Douglas W. Jordan, Anthony E. D’Agostino, and Robert H. Gillespie: Outcrop gamma-ray logging to improve understanding of subsurface well log correlations / Geological Society, London, Special Publications, 65:3-19, doi:10.1144/GSL.SP.1992.065.01.02 --- I. R. Hatton, M. Reeder, M. St. J. Newman, and D. Roberts: Techniques and applications of petrophysical correlation in submarine fan environments, early Tertiary sequence, North Sea / Geological Society, London, Special Publications, 65:21-30, doi:10.1144/GSL.SP.1992.065.01.03 --- Lawrence T. Bourke: Sedimentological borehole image analysis in clastic rocks: a systematic approach to interpretation / Geological Society, London, Special Publications, 65:31-42, doi:10.1144/GSL.SP.1992.065.01.04 --- Philippe A. Pezard, Richard N. Hiscott, Michael A. Lovell, Albina Collela, and Alberto Malinverno: Evolution of the Izu-Bonin intraoceanic forearc basin, western Pacific, from cores and FMS images / Geological Society, London, Special Publications, 65:43-50,NP-NP,51-69, doi:10.1144/GSL.SP.1992.065.01.05 --- A. R. M. Salimullah and D. A. V. Stow: Application of FMS images in poorly recovered coring intervals: examples from ODP Leg 129 / Geological Society, London, Special Publications, 65:71-86, doi:10.1144/GSL.SP.1992.065.01.06 --- A. R. M. Salimullah and D. A. V. Stow: Wireline log signatures of resedimented volcaniclastic facies, ODP Leg 129, West Central Pacific / Geological Society, London, Special Publications, 65:87-97, doi:10.1144/GSL.SP.1992.065.01.07 --- N. Ruhovets, R. Rau, M. Samuel, H. Smith, Jr., and M. Smith: Evaluating thinly laminated reservoirs using logs with different vertical resolution / Geological Society, London, Special Publications, 65:99-121, doi:10.1144/GSL.SP.1992.065.01.08 --- Erik Bølviken, Geir Storvik, Dag Erik Nilsen, Erling Siring, and Dirk Van Der Wel: Automated prediction of sedimentary facies from wireline logs / Geological Society, London, Special Publications, 65:123-139, doi:10.1144/GSL.SP.1992.065.01.09 --- Gavin I. F. Cameron: Analysis of dipmeter data for sedimentary orientation / Geological Society, London, Special Publications, 65:141-154, doi:10.1144/GSL.SP.1992.065.01.10 --- Fractures and Stress --- R. R. Hillis and A. F. Williams: Borehole breakouts and stress analysis in the Timor Sea / Geological Society, London, Special Publications, 65:157-168, doi:10.1144/GSL.SP.1992.065.01.11 --- Najwa A. Yassir and Maurice B. Dusseault: Stress trajectory determinations in southwestern Ontario from borehole logs / Geological Society, London, Special Publications, 65:169-177, doi:10.1144/GSL.SP.1992.065.01.12 --- S. M. Cowgill, P. G. Meredith, S. A. F. Murrell, and N. R. Brereton: In situ stress orientations in the Witch Ground Graben, North Sea, revealed by borehole breakouts: preliminary results / Geological Society, London, Special Publications, 65:179-184, doi:10.1144/GSL.SP.1992.065.01.13 --- Brian E. Hornby and Stefan M. Luthi: An integrated interpretation of fracture apertures computed from electrical borehole scans and reflected Stoneley waves / Geological Society, London, Special Publications, 65:185-198, doi:10.1144/GSL.SP.1992.065.01.14 --- D. Goldberg, C. Broglia, and K. Becker: Fracture permeability and alteration in gabbro from the Atlantis II Fracture Zone / Geological Society, London, Special Publications, 65:199-210, doi:10.1144/GSL.SP.1992.065.01.15 --- J. S. Bell, G. Caillet, and J. Adams: Attempts to detect open fractures and non-sealing faults with dipmeter logs / Geological Society, London, Special Publications, 65:211-220, doi:10.1144/GSL.SP.1992.065.01.16 --- Martin H. Bremer, Johannes Kulenkampff, and Jürgen R. Schopper: Lithological and fracture response of common logs in crystalline rocks / Geological Society, London, Special Publications, 65:221-234, doi:10.1144/GSL.SP.1992.065.01.17 --- C. J. MacLeod, L. M. Parson, W. W. Sager, and the ODP Leg 135 Scientific Party: Identification of tectonic rotations in boreholes by the integration of core information with Formation MicroScanner and Borehole Televiewer images / Geological Society, London, Special Publications, 65:235-246, doi:10.1144/GSL.SP.1992.065.01.18 --- J. T. Adams, J. K. Ayodele, J. Bedford, C. H. Kaars-Sijpesteijn, and N. L. Watts: Application of dipmeter data in structural interpretation, Niger Delta / Geological Society, London, Special Publications, 65:247-263, doi:10.1144/GSL.SP.1992.065.01.19 --- P. D. Jackson, S. Shedlock, J. Willis-Richards, and A. S. P. Green: Enhanced resolution resistivity logging for fracture studies / Geological Society, London, Special Publications, 65:265-274, doi:10.1144/GSL.SP.1992.065.01.20 --- Physical Properties --- Arne Marius Raaen: High-frequency pseudo-Rayleigh waves as a new indicator of shear velocity / Geological Society, London, Special Publications, 65:277-283, doi:10.1144/GSL.SP.1992.065.01.21 --- C. McCann and J. Sothcott: Laboratory measurements of the seismic properties of sedimentary rocks / Geological Society, London, Special Publications, 65:285-297, doi:10.1144/GSL.SP.1992.065.01.22 --- C. M. Griffiths, N. R. Brereton, R. Beausillon, and D. Castillo: Thermal conductivity prediction from petrophysical data: a case study / Geological Society, London, Special Publications, 65:299-315, doi:10.1144/GSL.SP.1992.065.01.23 --- D. M. McCann and D. C. Entwisle: Determination of Young’s modulus of the rock mass from geophysical well logs / Geological Society, London, Special Publications, 65:317-325, doi:10.1144/GSL.SP.1992.065.01.24 --- Kjetil Gran, Knut Bjørlykke, and Per Aagaard: Fluid salinity and dynamics in the North Sea and Haltenbanken basins derived from well log data / Geological Society, London, Special Publications, 65:327-338, doi:10.1144/GSL.SP.1992.065.01.25 --- Per-Gunnar Alm: The Temperature Decay Log: a different approach to presenting a temperature survey / Geological Society, London, Special Publications, 65:339-348, doi:10.1144/GSL.SP.1992.065.01.26 --- P. L. Ølgaard: A new approach to the interpretation of nuclear borehole logs / Geological Society, London, Special Publications, 65:349-358, doi:10.1144/GSL.SP.1992.065.01.27 --- Mineralogy and Geochemistry --- P. K. Harvey and M. A. Lovell: Downhole mineralogy logs: mineral inversion methods and the problem of compositional colinearity / Geological Society, London, Special Publications, 65:361-368, doi:10.1144/GSL.SP.1992.065.01.28 --- K. J. Myers and K. F. Jenkyns: Determining total organic carbon contents from well logs: an intercomparison of GST data and a new density log method / Geological Society, London, Special Publications, 65:369-376, doi:10.1144/GSL.SP.1992.065.01.29 --- R. C. Selley: The third age of wireline log analysis: application to reservoir diagenesis / Geological Society, London, Special Publications, 65:377-387, doi:10.1144/GSL.SP.1992.065.01.30 --- M. J. Cheshire and B. W. Sellwood: Sandstone diagenesis: framework of a forward modelling approach by integrating wireline and other geological data / Geological Society, London, Special Publications, 65:389-394, doi:10.1144/GSL.SP.1992.065.01.31