Developments And Interactions Of The Precambrian Atmosphere Lithosphere And Biosphere

Selection of papers from the IGCP Project 157 and 160 meeting at the Univ. Nacional Autonoma de Mexico, 11-14 Jan. 1982

Since 1964, the time when the Upper Mantle Project was started, the Precambrian continental crust has been studied in considerable detail in many areas. Multidisciplinary studies, using modern tools and techniques have resulted in increasing levels of accuracy. The Precambrian continental crust has been subjected to several thermal events and multiple episodes of deformation. These events have obliterated the scenario produced by early events and present-day efforts are directed towards evaluating the cause-effect processes of each event. How far back the known geological processes of the Phanerozoic can be extended into the Precambrian is one of the main questions. The present volume provides data and interpretations which will help in formulating the answer to some of these questions. The book contains 30 contributions resulting from researches on almost all the important Precambrian terranes.

Focusing on the Precambrian in the central part of the Fennoscandian Shield, the book combines the results from modern geological and geophysical research into a detailed petrologic, lithologic, and structural synthesis and interpretation of the Archean and Proterozoic of Finland. It will be of value to anyone interested in the evolution of the shield in particular and in Precambrian geology in general.

Recent developments have shown that many full and partial ophiolites are preserved in Precambrian cratons. This book provides a comprehensive description and discussion of the field aspects, geochemistry, geochronology and structure of the best of these ophiolites. It also presents syntheses of the characteristics of ophiolites of different ages, and an analysis of what the characteristics of these ophiolites mean for the thermal and chemical evolution of the earth. This title emphasizes new studies of Precambrian Geology that have documented ophiolites, ophiolitic fragments, and ophiolitic melanges in many Precambrian terranes. Each chapter focuses on individual Precambrian ophiolites or regions with numerous Precambrian ophiolites, and covers field aspects, petrology, geochemistry, geochronology, and other descriptive aspects of these ophiolites, it also delves into more theoretical and speculative aspects about the interpretation of the significance of these ancient ophiolites.

Diagenesis is a highly developed, interdisciplinary field of study. It is reciprocal in that it borrows from numerous scientific or technological specialities and then, in turn, repays them with useful results. Too often, however, the information gained and concepts developed remain unintegrated instead of being utilized quickly by several related earth-science fraternities. This volume, the first of a multi-volume work, attempts to bring together such information, thereby assisting the individual and the research group in keeping up with the data explosion. There is no end in sight to diagenetic research because of its wide practical and intellectual appeals. Consequently, periodic reviews, such as presented in this volume, are greatly needed.