This is the first book to deal specifically with the procedures used in the analysis of structural relationships and the determination of structural successions in complexly deformed rocks such as migmatites and gneisses. The establishment of structural successions enables: The rigorous control of the dating of specific events in the deformational history by constraining the sites of the dated rocks within the structural succession; The establishment of the time span of orogenic events throughout the structural succession, and the rate of orogenic processes;Their comparison to be used as a basis for correlation between dismembered and separated crustal segments in continental reconstructions;The resolution of the complex relationships between deformed ore bodies and host rocks in high grade terranes, and hence determination of the structural control of ore bodies, an essential part of any successful geological exploration, and a precondition to efficient exploitation. With its new approach, and the use of practical field examples from various parts of the world, this highly illustrated work will form an invaluable reference resource for postgraduates, lecturers and researchers in the structural and isotope geology of high-grade metamorphic terranes, as well as for exploration and survey geologists working in the field. Dr Alaric M. Hopgood who holds an Honorary Readership at the University of St Andrews, Scotland, was a Reader in the Department of Geology there until 1995.
The origin of granite has for long fascinated geologists though serious debate on the topic may be said to date from a famous meeting of the Geological Society of France in 1847. My own introduction to the subject began exactly one hundred years later when, in an interview with Profes sor H. H. Read, I entered his study as an amateur fossil collector and left it as a committed granite petrologist - after just ten minutes! I can hardly aspire to convert my reader in so dramatic a way, yet this book is an attempt, however inadequate, to pass on the enthusiasm that I inherited, and which has been reinforced by innumerable discussions on the outcrop with granitologists of many nationalities and of many shades of opinion. Since the 1960s, interest in granites has been greatly stimulated by the thesis that granites image their source rocks in the inaccessible deep crust, and that their diversity is the result of varying global tectonic context. So great a body of new data and new ideas has accumulated that my attempt to review the whole field of granite studies must carry with it a possible charge of arrogance, especially as I have adopted the teaching device of presenting the material from a personal point of view with its thinly disguised prejudices.