Metamorphic Geology: An Introduction to Tectonic and Metamorphic Processes

ISBN-13: 9780045510580 / Angielski / Miękka / 1982 / 146 str.

Con Gillen; Cornelius Gillen

Opis

This book is about metamorphic rocks: the processes involved in their formation and the reasons why they occur at particular places on the continents. It has been written to serve as an elementary text on the subjects of metamorphism and mountain building for non-specialist stu- dents of geology. It will be equally useful where geology is either the main or subsidiary subject and could be used by students intending to advance further in geology (the list of advanced texts in the further reading section would be more appropriate to such students). My inten- tion in writing this book has been to try to dispel the notion that metamorphism comprises the 'haunted wing' of geology. Admittedly, there are rather a large number of technical terms in the book, but I hope that after working through it you will not find metamorphism an unduly difficult or obscure aspect of geology. Throughout, I have emphasised the strong links between mountain building, plate tectonics and metamorphic processes. The book introduces metamorphic rocks by considering their textures and field relations, then moves on to deal with the factors controlling metamorphism. Case studies of areas of metamorphic rocks are then presented in the context of modern theories of the Earth's activity, and the place of metamorphic rocks in the formation of ancient and young mountain belts is analysed. New technical terms and concepts are explained in context as they are introduced, important terms being emphasised in bold print.

Spis treści

1 Introduction — What are metamorphic rocks?.- What does a metamorphic rock look like?.- The make-up of metamorphic rocks.- Metamorphic rock textures.- Metamorphic reactions.- Field relations of metamorphic rocks.- Uses of metamorphic rocks.- What this book is about.- Summary.- Exercise.- 2 How rocks are changed — The factors controlling metamorphism.- The Earth’s heat.- Where does the heat come from?.- How does the heat travel?.- Heat flow.- The geothermal gradient.- Pressure in the Earth.- What is pore-fluid pressure?.- Stress and strain in the crust.- The driving force for metamorphic reactions.- Equilibrium in metamorphic reactions.- Crystal growth during metamorphism.- Diffusion during metamorphism.- Recrystallisation during metamorphism.- Metamorphism and crustal processes.- Plate tectonics and metamorphic rocks.- Metamorphic grades, zones and facies.- Classifying metamorphic processes.- Summary page.- Exercises.- 3 Metamorphic terrains I.- Contact metamorphism.- Dynamic metamorphic rocks.- Summary.- Exercises.- 4 Metamorphic terrains II.- Regional metamorphism.- Metamorphic rocks in Precambrian shields.- High-pressure—low-temperature regional metamorphism.- Summary.- Exercises.- 5 Mountain building and metamorphic rocks.- Continental collision zones.- Continent/ocean collision zones.- Metamorphic belts through time.- Heat flow with time.- Evolution of the Earth’s crust.- Metamorphic rocks and the early history of the Earth.- Summary.- Exercises.- 6 The timing of metamorphic events.- Metasomatism — bulk chemical change.- Further reading.- Answers to exercises.