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.

The main goal of this book is to provide a modern comprehensive statement on the Earth's Precambrian crust. It uses geographic and tectonic location, lithostratigraphy, geochronology, and petrogenesis as a basis for considering Precambrian coastal evolution--including the role of plate tectonics. Detailed consideration is given to the endogenic and exogenic processes which formed the continental crust and also to its subsequent secular evolution across Precambrian time**An essential reference volume for every Precambrian geologist.

The book deals with the record of important Neoproterozoic to Early Palaeozoic events in southwestern Gondwana, that heralded the Cambrian explosion and the dawn of modern ecosystems. It contains a detailed account of the Neoproterozoic to Cambrian geological record in a poorly-known part of the world, which is at the same time key to understand fundamental processes at the Proterozoic-Cambrian transition. The emphasis is placed on litho-, bio-, chemostratigraphy and magmatism. The palaeoclimatic, tectonic, evolutionary radiation and extinction events and associated mineralizations will be identified and discussed. A synthesis of all data is provided at the end of the book, integrating the data from all cratons and fold belts in southwestern Gondwana. The events will be individualized, their impact discussed and correlations between different successions both within and outside Gondwana proposed.The book is organized in three sections. Section one is an introduction to the neoproterozoic and Cambrian seen as a time of upheavals, extremes and innovations. Section two comprises nineteen chapters dealing with the neoproterozoic-Cambrian events in southwestern Gondwana. Section three will provide a synthesis on every major topic, and a critical assessment of the global implications of the presented data. - The book deals with the record of important Neoproterozoic to Early Palaeozoic events in southwestern Gondwana, that heralded the Cambrian explosion and the dawn of modern ecosystems - It contains a detailed account of the Neoproterozoic to Cambrian geological record in a poorly-known part of the world, which is at the same time key to understand fundamental processes at the Proterozoic-Cambrian transition - The emphasis is placed on litho-, bio-, chemostratigraphy and magmatism

In this book the editors strive to cover all primary (i.e. non-applied) topics in Precambrian geology in a non-partisan way, by using a large team of international authors to present their datasets and highly divergent viewpoints. The chapters address: celestial origins of Earth and succeeding extraterrestrial impact events; generation of continental crust and the greenstone-granite debate; the interaction of mantle plumes and plate tectonics over Precambrian time; Precambrian volcanism, emphasising komatiite research; evolution and models for Earth's hydrosphere and atmosphere; evolution of life and its influence on Precambrian ocean chemistry and chemical sedimentation; sedimentation through Precambrian time; the application of sequence stratigraphy to the Precambrian rock record. Each topic is introduced and a non-partisan closing commentary provided at the end of each chapter. The final chapter blends the major geological events and rates at which important processes occurred into a synthesis, which postulates a number of "event clusters" in the Precambrian when significant changes occurred in many natural systems and geological environments. Also available in paperback, ISBN: 0-444-51509-7

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.

Principles of Precambrian Geologyis an update to the 1991 book, Precambrian Geology: The Dynamic Evolution of the Continental Crust, by the same author. The new edition covers the same topics in a more concise and accessible format and is replete with explanatory figures, tables, and illustrations. The book serves as a modern comprehensive statement on the Earth's Precambrian crust, covering the main aspects of distribution, lithiostratigraphy, age, and petrogenesis of Precambrian rocks by continent within the context of the Earth's evolving continental crust. Principles of Precambrian Geology provides a suitable framework for assessing various Earth dynamic and biospheric hypotheses, including the modern plate tectonic paradigm and the Gaian hypothesis. Despite the concise format, the new edition provides extensive updated references to support the information presented. It is designed to serve the needs of student, teacher, explorationist and general student of the continental crust. - Updated to provide more concise accessible information - Extensive illustrations, tabulations, and maps - Provides a framework for assessing recent hypothesis on Earth dynamics - Covers main aspects of distribution, lithostratigraphy, age, and protogenesis of Precambrian rocks

This volume draws together and generalises new geological, geochronological, petrological and geophysical material for the two fundamental continental geostructures within the USSR - ancient cratons and Phanerozoic fold belts. It provides a complete Precambrian history for each tectonic province or "geoblock", with emphasis on the early Precambrian as opposed to the late. The characteristics of lithological-structural complexes and their correlations are presented in detail. Analysis of the sedimentary, magmatic and metamorphic processes is provided, paying special attention to the sequence of their evolution and isotopic data. This work will be of interest to geologists concerned with the problems of structure and evolution of the Precambrian lithology.