E-grāmata: Field Description of Metamorphic Rocks

"Metamorphic rocks form a substantial proportion of the material that makes up the Earth's crust, and metamorphic processes have been almost continually occurring throughout geological time since the origin of that crust. Metamorphism can be defined simply as the process by which sedimentary or igneous rocks are transformed (metamorphosed) by re-crystallisation due to changes in pressure, temperature, or fluid conditions. To complicate matters somewhat, metamorphism can of course also act on rocks that have already been metamorphosed previously, building layer upon layer of complexity into those rocks that record field evidence of some of Earth's most dynamic processes. Our understanding of metamorphism is somewhat limited by the fact that we are unable to directly observe it happening to the rocks. As you read this, metamorphism is in action all around the planet, in all aspects of the Earth's plate tectonic system (e.g. Figure 1.1), but we cannot directly see it (generally because it happens at depth and very slowly). In order to understand the processes and products of metamorphism and alteration in rocks, detailed fieldwork, petrography, experimental studies, and numerical modelling are required. It is important to note, however, that the very originof metamorphic petrology (the science of understanding the distribution, structure, and origin of metamorphic rocks) is rooted in a tradition of careful and systematic field observation, and that this remains an absolute cornerstone of the discipline today"--

This hand pocket-sized field guide describes how metamorphic rocks and rock masses maybe observed, recorded and mapped in the field. Written at a level suitable for earth science undergraduate students, this book is an essential tool for any geologist—student, professional or amateur—faced with the task of making a general description of an area of metamorphic rocks. A clear, systematic framework, together with numerous colour diagrams, illustrations and checklists, enables readers to produce useful and broadly similar descriptions, despite possible differences of background or specialist interest. Additional information is also provided to aid those who are undertaking a field mapping and report course.

• Shows the reader how to observe metamorphic rocks in the field, from the outcrop to the hand specimen scale
• Fully revised and updated to incorporate new developments in the field
• User-friendly and accessible writing style Including a revised format with tabbed sections for easy navigation
• Key topics covered include; classification and mapping of metamorphic rocks, understanding key textures and fabrics, and details on contacts and fault zones.