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 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.

Syntheses of the geology of major areas of the Earth's crust are increasingly needed in order that the features of, and the problems associated with, the secular evolution of the continents can be understood by a wide audience. Southern Africa is fortunate in having a remarkable variety of geological environments developed without many breaks over 3. 8 Ga, and many of the rock groups are household names throughout the geological world. In one respect the geology of Southern Africa is particularly important: cratonization clearly began as early as 3. 0 Ga ago, in contrast to about 2. 5 Ga in most other continental areas such as North America. This book documents very well the remarkable change in tectonic conditions that took place between the Early and Mid-Precambrian; we have here evidence of the very earliest development of rigid lithospheric plates. This book is a tribute to the multitudes of scientists who have worked out the geology of Southern Africa over many years and decades. Whatever their discipline, each provided a step in the construction of this fascinating story of 3. 8 Ga of crustal development. In the book the reader will find a detailed review of the factual data, together with a balanced account of interpretative models without the indulgence of undue speculation. One of its attractions is its multidisciplinary approach which provides a stimulating challenge to the reader.