Early Precambrian Basic Magmatism

Basic magmatic rocks make up approximately three-quarters of the crust ofthe present day Earth. Because we can observe and study the volcanic products of present day tectonic regimes comprehensively, we can shed light on ancient tectono-magmatic provinces, and thereby deduce the petrogenesis and evolution of the oldest basic rocks. This is the primary objective of this book. The book was conceived in order to provide a comprehensive review of the basic rocks produced during the first half of the Precambrian, i.e. the Archaean and early Proterozoic, to about 1.8 Ga years ago. Two major questions are addressed. First, what basic magmas were generated during the early Precambrian: were these magmas globally uniform, and to what extent were prevailing tectonic controls and compo sitions analogous to those of the present day? Clearly, this can be answered only by bringing together fundamental information about all relevant basic magmatic events. Second, is there any systematic temporal variation in the nature of basic suites, and what implications might such variations have on our interpretations of early Earth history? Are there important differences between early Archaean, late Archaean, Proterozoic and modern basic magmatic suites? The book uses two approaches to address these questions. Early chapters examine the fundamental characteristics of these basic rocks, whilst later chapters assess regional distribution and development by providing an overview of each major early Precambrian craton.

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

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.

Dyke swarms are remnants of large igneous provinces, and are pointers of continental break-up events, as well as indicators for ancient continental reconstructions. These global geodynamic aspects are of crucial significance in tectonics, and with recent developments in high-precision age, dating it has become possible to enter these short-lived ma

As a final product of the International Geological Correlation Program (IGCP) Project 217, this volume brings together significant advances in the understanding of Proterozoic crustal evolution. This IGCP Project focussed on nine research objectives: 1) Comparison of Archean and Proterozoic supracrustal assemblages to more fully understand differences between Archean and post-Archean tectonic regimes; 2) To more fully understand the geochemical differences between Archean and post-Archean sediments and to evaluate the various factors that control sediment composition; 3) From combined U/Pb zircon and whole-rock Sm/Nd studies, to see if the apparent 2.4-2.0 continental crust "generation gap" is real; 4) To employ new techniques in the dating of individual zircons to more fully understand Proterozoic tectonic history and the role of crustal reworking; 5) From trace element ratios and Nd isotopic data from basalts, to better understand Proterozoic mantle evolution; 6) To encourage more detailed studies of the anorogenic granite-anorthosite association to better understand its origin and significance in terms of crustal evolution; 7) From combined Nd, Pb, and Sr isotopic data, to more precisely estimate the amount of new continental crust formed during the Proterozoic; 8) To encourage joint P-T and geochronological studies of Proterozoic and high-grade terranes to better understand Proterozoic orogenesis: and 9) To try and understand why hydrothermal precious metal deposits are relatively rare in the Proterozoic compared to both the Archean and the Phanerozoic. The book should be of interest to professionals in the geosciences (especially geochemists, petrologists and structural geologists) and graduate students in the same fields.

The variety of volcanic activity in the Solar System is widely recognised, yet the majestic sequences of magmatic processes that operate within an active planet are much less well known. Providing an exposition of igneous rocks, magmas and volcanic erupsions, this book brings together magnetic and volcanic data from different tectonic settings, and planets, with explanations of how they fit together. It systematically examines composition, origin and evolution of common igneous rocks, yet also examines a variety of rare magnetic rocks that play a crucial role in the global magma/igneous rock system.

Magnatism is the only true endogenic process for generating new material on the Earth's surface. Obviously, magmatism and tectonic movements are reflections of geodynamics, that is, physical processes which occur in deep-seated environments. What are the interrelationships between magmatism and tectronics? How did the character of terrestrial magmatism change through time and are there any irregularities in this process?