Metamorphic Rocks as the Key to Understanding Geodynamic Processes


Book Description

This book is a collection of works on new research in metamorphic geology. The chapters cover a broad range of subjects, including new advances as well as field-based approaches to and novel technologies for solving metamorphic geology problems, including micromineralogy, microanalytical, geostatistical, microtextural, Geographical Information Systems (GIS), and remote sensing methods.




Petrology of the Metamorphic Rocks


Book Description

There has been a great advance in the understanding of processes of meta morphism and of metamorphic rocks since the last edition of this book appeared. Methods for determining temperatures and pressures have become almost routine, and there is a wide appreciation that there is not a single temperature and pressure of metamorphism, but that rocks may preserve, in their minerals, chemistry and textures, traces of their history of burial, heating, deformation and permeation by fluids. However, this excit ing new knowledge is still often difficult for non-specialists to understand, and this book, like the first edition, aims at enlightenment. I have concen trated on the interpretation of the plate tectonic settings of metamorphism, rather than following a geochemical approach. Although there is an impress ive degree of agreement between the two, I believe that attempting to discover the tectonic conditions accompanying rock recrystallization will more readily arouse the interest of the beginner. I have used a series of case histories, as in the first edition, drawing on my own direct experience as far as possible. This m




Epidotes


Book Description

Volume 56 of the Reviews in Mineralogy and Geochemistry reviews the current state of knowledge on the epidote minerals with special emphasis on the advances that were made since the comprehensive review of Deer et al. (1986). In the Introduction, we review the structure, optical data and crystal chemistry of this mineral group, all of which form the basis for understanding much of the following material in the volume. In addition, we provide some information on special topics, such as morphology and growth, deformation behavior, and gemology. Thermodynamic properties (Chapter 2, Gottschalk), the spectroscopy of the epidote minerals (Chapter 3, Liebscher) and a review of the experimental studies (Chapter 4, Poli and Schmidt) constitute the first section of chapters. These fields are closely related, and all three chapters show the significant progress over the last years, but that some of the critical questions such as the problem of miscibility and miscibility gaps are still not completely solved. This section concludes with a review of fluid inclusion studies (Chapter 5, Klemd), a topic that turned out to be of large interest for petrogenetic interpretation, and leads to the description of natural epidote occurrences in the second section of the book. These following chapters review the geological environments of the epdiote minerals, from low temperature in geothermal fields (Chapter 6, Bird and Spieler), to common metamorphic rocks (Chapter 7, Grapes and Hoskin) and to high- and ultrahigh pressure (Chapter 8, Enami, Liou and Mattinson) and the magmatic regime (Chapter 9, Schmidt and Poli). Allanite (Chapter 10, Gieré and Sorensen) and piemontite (Chapter 11, Bonazzi and Menchetti), on which a large amount of information is now available, are reviewed in separate chapters. Finally trace element (Chapter 12, Frei, Liebscher, Franz and Dulski) and isotopic studies, both stable and radiogenic isotopes (Chapter 13, Morrison) are considered. We found it unavoidable that there is some overlap between individual chapters. This is an inherited problem in a mineral group such as the epidote minerals, which forms intensive solid solutions between the major components of rock forming minerals as well as with trace elements.




Metamorphic Geology


Book Description

In Earth evolution, mountain belts are the loci of crustal growth, reworking and recycling. These crustal-scale processes are unravelled through microscale investigations of textures and mineral assemblages of metamorphic rocks. Multiple episodes of metamorphism, re-equilibration and deformation, however, generally produce a complex and tightly interwoven pattern of microstructures and assemblages. Over the last two decades, the combination of advanced computing and technological capabilities with new concepts has provided a vast array of novel petrological tools and high-resolution/high-sensitivity techniques for microanalysis and imaging. Such novel approaches are proving fundamental to untangling the enigma represented by metamorphism with an unprecedented level of detail and confidence. As a result, the first decade and a half of this century has already seen the tumultuous development of new research avenues in metamorphic petrology. This book aims to provide a timely overview of the state of the art of this field, of newly developed petrological techniques, future advancements and significant new case studies.




Petrogenesis of Metamorphic Rocks


Book Description

Metamorphic rocks are one of the three classes of rocks. Seen on a global scale they constitute the dominant material of the Earth. The understanding of the petrogenesis and significance of metamorphic of geological education. rocks is, therefore, a fundamental topic There are, of course, many different possible ways to lecture on this theme. This book addresses rock metamorphism from a relatively pragmatic view point. It has been written for the senior undergrad uate or graduate student who needs practical knowledge of how to interpret various groups of minerals found in metamorphic rocks. The book is also of interest for the non-specialist and non-petrolo gist professional who is interested in learning more about the geolo gical messages that metamorphic mineral assemblages are sending, as well as pressure and temperature conditions of formation. The book is organized into two parts. The first part introduces the different types of metamorphism, defines some names, terms and graphs used to describe metamorphic rocks, and discusses principal aspects of metamorphic processes. Part I introduces the causes of metamorphism on various scales in time and space, and some principles of chemical reactions in rocks that accompany metamorphism, but without treating these principles in detail, and presenting the thermodynamic basis for quantitative analysis of reactions and their equilibria in metamorphism. Part I also presents concepts of metamorphic grade or intensity of metamorphism, such as the metamorphic-facies concept.




Encyclopedia of Geochemistry


Book Description

The Encyclopedia is a complete and authoritative reference work for this rapidly evolving field. Over 200 international scientists, each experts in their specialties, have written over 330 separate topics on different aspects of geochemistry including geochemical thermodynamics and kinetics, isotope and organic geochemistry, meteorites and cosmochemistry, the carbon cycle and climate, trace elements, geochemistry of high and low temperature processes, and ore deposition, to name just a few. The geochemical behavior of the elements is described as is the state of the art in analytical geochemistry. Each topic incorporates cross-referencing to related articles, and also has its own reference list to lead the reader to the essential articles within the published literature. The entries are arranged alphabetically, for easy access, and the subject and citation indices are comprehensive and extensive. Geochemistry applies chemical techniques and approaches to understanding the Earth and how it works. It touches upon almost every aspect of earth science, ranging from applied topics such as the search for energy and mineral resources, environmental pollution, and climate change to more basic questions such as the Earth’s origin and composition, the origin and evolution of life, rock weathering and metamorphism, and the pattern of ocean and mantle circulation. Geochemistry allows us to assign absolute ages to events in Earth’s history, to trace the flow of ocean water both now and in the past, trace sediments into subduction zones and arc volcanoes, and trace petroleum to its source rock and ultimately the environment in which it formed. The earliest of evidence of life is chemical and isotopic traces, not fossils, preserved in rocks. Geochemistry has allowed us to unravel the history of the ice ages and thereby deduce their cause. Geochemistry allows us to determine the swings in Earth’s surface temperatures during the ice ages, determine the temperatures and pressures at which rocks have been metamorphosed, and the rates at which ancient magma chambers cooled and crystallized. The field has grown rapidly more sophisticated, in both analytical techniques that can determine elemental concentrations or isotope ratios with exquisite precision and in computational modeling on scales ranging from atomic to planetary.




Petrogenesis of Metamorphic Rocks


Book Description

This new edition of the classic textbook presents a large number of diagrams showing the stability relations among minerals and groups of minerals found in metamorphic rocks. The diagrams help to determine the pressure and temperature conditions under which a given set of metamorphic rocks may have formed. Other parameters that control metamorphic mineral assemblages are also discussed and pitfalls resulting from simplifications and generalizations are highlighted. The book discusses the most common metamorphic rock types, their nomenclature, structure and graphical representation of their mineral assemblages. Part I defines basic principles of metamorphism, introduces metamorphic processes, geologic thermometry and barometry and defines metamorphic grade. Part II presents in a systematic way mineralogical changes and assemblages found in the most common types of metamorphic rocks. The computation of diagrams is based on recent advances in quantitative petrology and geochemistry. An extensive bibliography, including the key contributions and classic papers in the field, make it an invaluable source book for graduate students and professional geologists.




GEOLOGY- Volume II


Book Description

Geology is the Component of Encyclopedia of Earth and Atmospheric Sciences, in the global Encyclopedia of Life Support Systems (EOLSS)), which is an integrated compendium of twenty Encyclopedias. The theme on geology in the Encyclopedia of Earth and Atmospheric Sciences, presents many aspects of geology under the following nine different topics: The Organized Earth.; Tectonics and Geodynamics; Igneous and Metamorphic Petrology; Sedimentary Geology and Paleontology; Overview of the Mineralogical Sciences; Geology of Metallic and Non-Metallic Mineral Resources; Regional Geology; Geology of Petroleum, Gas, and Coal; Environmental and Engineering Geology.




Formation and Crust-Mantle Geodynamic Processes of the Neoarchean K-rich Granitoid Belt in the Southern Range of Eastern Hebei-Western Liaoning Provinces, North China Craton


Book Description

Meso- to Neoarchean is a critical transitional period for the formation and evolution of continental crust and the corresponding geodynamic mechanisms, during which the average composition of continental crust gradually shifted from Na-enriched to K-enriched. However, the ultimate source of K and its enrichment mechanism in continental crust are still enigmatic. Moreover, fierce controversies remain on the Precambrian subdivision and late Archean geodynamic models of the North China Craton (NCC). Archean basement terranes in the Eastern Hebei-Western Liaoning Provinces, northern NCC display characteristic lithological zonation similar to those developed in modern convergent plate margins, and from northwest to southeast can be subdivided into the MORB-type tholeiite belt, oceanic arc tectonic belt, and K-rich granitoid belt. This book reports systematic field geological, petrographic, structural, whole-rock geochemical, and zircon U-Pb-Hf-O isotopic data for the various late Neoarchean lithological assemblages of the K-rich granitoid belt. Their deformational characteristics and petrogenesis are discussed in detail, and integrated with their spatiotemporal relationships and metamorphic features, a late Neoarchean active continental margin setting with multi-stage trench retreats and subsequent arc-continent collision is proposed to account for the formation and evolution of the K-rich granitoid belt. It also throws light upon the ultimate source and enrichment mechanism of K in the late Archean continental crust by comparing K-rich granitoid belt with the adjacent oceanic arc tectonic belt.




Reconstruction of the Paleo-Asian Ocean


Book Description

This Proceedings volume contains selected papers from two symposia which were held during the 29th International Geological Congress, Kyoto, Japan, 24 August--3 September, 1992. The first symposium --- ''Reconstruction of the Paleo-Asian Ocean'' --- contains 11 papers from a group of scientists working together in an international project of the same name. The goal of the project is to collect and evaluate petrologic and tectonic data within specific terranes so as to understand the geodynamic processes leading to the amalgamation of Asia. These papers represent vital geological discussions for interpreting the geodynamic maps being produced by the project. From the second symposium of this volume --- ''Quaternary Environmental Change'' --- 14 papers were selected. The wide range of topics can be divided as follows: Deep sea core analysis; Coral reef and nearshore environment; Paleoenvironmental analysis; Tephras, Loess and Pedology; River morphology and others.