Petrologic analysis of first-cycle clastic sediments derived from a single source in an arid environment provides a means to determine how well they resemble the petrology and geochemistry of their source. The Stepladder Mountains, located in the Mojave Desert of southeastern California, represents a well-controlled location (i.e., arid environment; single, known source; short transport distance) to examine how naturally formed sediments acquire their compositions. Compositional modifications associated with sediment production were resolved through direct examination of the weathered components (regolith, grus, and sediments). Sediment compositions strongly vary by grain size, indicating that, after the source itself, hydrodynamic sorting played the dominant role in shaping the composition of Stepladder sediment. Traditional petrographic and geochemical provenance-seeking indicators were also tested to determine their efficacy. Plots employing major element abundances, including Al2O3- CaO*+Na2O-K2O (A-CN-K) and Al2O3-CaO*+Na2O+K2O-Fe2O3+MgO (A-CNK-FM) ternary plots, proved to be the most accurate at identifying the lack of chemical weathering and the importance of sediment sorting in the production of Stepladder sediments. Plots using trace and rare earth element concentrations reveal the significant modifications that sorting can have on sediment composition. All of the Stepladder sediments are enriched in immobile transition metals, most notably Sc, Cr, Ni, and Co, and even though the sediment sourced from a single pluton, compositions are consistent with the mixing of 10 - 20 % of a basaltic component. Sediment trace element ratios, including Th/Sc, Cr/Th, La/Sc, Th/Co, and Zr/Sc, can differ from average bedrock by up to a factor of 10. It must be known that moderate variations in composition and elemental ratios can be the result of sorting during sediment transport and do not necessarily indicate the mixing between sources.

This study tested whether transport distances (

The topic of sediment diagenesis is of fundamental importance to industry in the evaluation of hydrocarbon and water reservoir rocks. Detailed knowledge of the diagenetic textures, fabrics, and minerals, and a prediction of the regional diagenetic response, partly controls hydrocarbon recovery programmes. In other words, knowledge of the diagenesis can aid (or even control) conservation policy. Similarly, facies and diagenetic trends w.ithin basins can influence exploration policy. This volume incorporates the majority of the principal contributions given to the NATO Advanced Study Institute held in the University of Reading, U.K., from July 12th-25th, 1981, at which the major themes of carbonate and terrigenous clastic sediments were treated sequentially from deposition to deep burial. Eighty selected scientists from twelve NATO and three other countries participated in the Institute. The keynote addresses which acted as the touchstones for discussion are presented here in the expectation that they will stimulate a still wider audience. We gratefully acknowledge the award of a grant from the Scientific Affairs Division of NATO to run the Institute, and also the cooperation of the University of Reading. Mrs. D. M. Powell helped in many ways with the organisation, and also retyped the entire manuscript of this book. A. Parker B. lv. Sellwood vii FACIES, SEQUENCES AND SAND-BODIES OF THE PRINCIPAL CLASTIC DEPOSITIONAL ENVIRONMENTS T.Elliott Department of Geology University College of Swansea Singleton Park, Swansea SA 2 8PP Wales, U.K.

The book on deposition, diagenesis, and weathering of organic matter-rich sediments is a summary of seven years of research work of the author at the Institute of Petroleum and Organic Geochemistry in J}lich. It contains a comparision of various depositional environments (lakes, deltas, seas)with respect to organic matter characteristics, a special chapter on the deposition of the Posidonia shale, a summary of organic matter maturation and related petroleum generation, and a chapter on the use of maturationparameters as calibration tools for numerical modelling of temperature histories of sedimentary basins. Also, microscopic effects of petroleum generation and oil to gas cracking are treated. The final chapters deal withcoals as source rocks for oil and gas and with the effects of weatheringon sediments which are rich in organic matter.

This fully revised and updated edition introduces the reader to sedimentology and stratigraphic principles, and provides tools for the interpretation of sediments and sedimentary rocks. The processes of formation, transport and deposition of sediment are considered and then applied to develop conceptual models for the full range of sedimentary environments, from deserts to deep seas and reefs to rivers. Different approaches to using stratigraphic principles to date and correlate strata are also considered, in order to provide a comprehensive introduction to all aspects of sedimentology and stratigraphy. The text and figures are designed to be accessible to anyone completely new to the subject, and all of the illustrative material is provided in an accompanying CD-ROM. High-resolution versions of these images can also be downloaded from the companion website for this book at: www.wiley.com/go/nicholssedimentology.

This book is intended to complement the author's 1996 book "The geology of fluvial deposits", not to replace it. The book summarizes methods of mapping and interpretation of fluvial depositional systems, with a detailed treatment of the tectonic, climatic and eustatic controls on fluvial depositional processes. It focuses on the preserved, ancient depositional record and emphasizes large-scale (basin-scale) depositional processes. Tectonic and climatic controls of fluvial sedimentation and the effects of base-level change on sequence architecture are discussed. Profusely illustrated and with an extensive reference to the recent literature, this book will be welcomed by the student and professional geologist alike.

John E. Mylroie and Ira D. Sasowsky' Caves occupy incongruous positions in both our culture and our science. The oldest records of modem human culture are the vivid cave paintings from southern France and northern Spain, which are in some cases more than 30,000 years old (Chauvet, et ai, 1996). Yet, to call someone a "caveman" is to declare them primitive and ignorant. Caves, being cryptic and mysterious, occupied important roles in many cultures. For example, Greece, a country with abundant karst, had the oracle at Delphi and Hades the god of death working from caves. People are both drawn to and mortified by caves. Written records ofcave exploration exist from as early as 852 BC (Shaw, 1992). In the decade of the 1920's, which was rich in news events, the second biggest story (as measured by column inches of newsprint) was the entrapment of Floyd Collins in Sand Cave, Kentucky, USA. This was surpassed only by Lindbergh's flight across the Atlantic (Murray and Brucker, 1979).