Chapter 6: Sedimentary and Metamorphic Rocks
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Editorial for Special Issue “Ore Genesis and Metamorphism: Geochemistry, Mineralogy, and Isotopes”
minerals Editorial Editorial for Special Issue “Ore Genesis and Metamorphism: Geochemistry, Mineralogy, and Isotopes” Pavel A. Serov Geological Institute of the Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia; [email protected] Magmatism, ore genesis and metamorphism are commonly associated processes that define fundamental features of the Earth’s crustal evolution from the earliest Precambrian to Phanerozoic. Basically, the need and importance of studying the role of metamorphic processes in formation and transformation of deposits is of great value when discussing the origin of deposits confined to varied geological settings. In synthesis, the signatures imprinted by metamorphic episodes during the evolution largely indicate complicated and multistage patterns of ore-forming processes, as well as the polygenic nature of the mineralization generated by magmatic, postmagmatic, and metamorphic processes. Rapid industrialization and expanding demand for various types of mineral raw ma- terials require increasing rates of mining operations. The current Special Issue is dedicated to the latest achievements in geochemistry, mineralogy, and geochronology of ore and metamorphic complexes, their interrelation, and the potential for further prospecting. The issue contains six practical and theoretical studies that provide for a better understanding of the age and nature of metamorphic and metasomatic transformations, as well as their contribution to mineralization in various geological complexes. The first article, by Jiang et al. [1], reports results of the first mineralogical–geochemical Citation: Serov, P.A. Editorial for studies of gem-quality nephrite from the major Yinggelike deposit (Xinjiang, NW China). Special Issue “Ore Genesis and The authors used a set of advanced analytical techniques, that is, electron probe microanaly- Metamorphism: Geochemistry, sis, X-ray fluorescence (XRF) spectrometry, inductively coupled plasma mass spectrometry Mineralogy, and Isotopes”. -
Metamorphic Rocks (Lab )
Figure 3.12 Igneous Rocks (Lab ) The RockSedimentary Cycle Rocks (Lab ) Metamorphic Rocks (Lab ) Areas of regional metamorphism Compressive Compressive Stress Stress Products of Regional Metamorphism Products of Contact Metamorphism Foliated texture forms Non-foliated texture forms during compression during static pressure Texture Minerals Other Diagnostic Metamorphic Protolith Features Rock Name Non-foliated calcite, dolomite cleavage faces of Marble Limestone calcite usually visible quartz quartz grains are Quartzite Quartz Sandstone intergrown Foliated clay looks like shale but Slate Shale breaks into layers muscovite, biotite very fine-grained, but Phyllite Shale has a sheen like satin muscovite, biotite, minerals are large Schist Shale may have garnet enough to see easily, muscovite and biotite grains are parallel to each other feldspar, biotite, has layers of different Gneiss Any protolith muscovite, quartz, minerals garnet amphibole layered black Amphibolite Basalt or Andesite amphibole grains Texture Minerals Other Diagnostic Metamorphic Protolith Features Rock Name Non-foliated calcite, dolomite cleavage faces of Marble Limestone calcite usually visible quartz quartz grains are Quartzite Quartz Sandstone intergrown Foliated clay looks like shale but Slate Shale breaks into layers muscovite, biotite very fine-grained, but Phyllite Shale has a sheen like satin muscovite, biotite, minerals are large Schist Shale may have garnet enough to see easily, muscovite and biotite grains are parallel to each other feldspar, biotite, has layers of different Gneiss Any protolith muscovite, quartz, minerals garnet amphibole layered black Amphibolite Basalt or Andesite amphibole grains Identification of Metamorphic Rocks 12 samples 7 are metamorphic 5 are igneous or sedimentary Protoliths and Geologic History For 2 of the metamorphic rocks: Match the metamorphic rock to its protolith (both from Part One) Write a short geologic history of the sample 1. -
Sediment Diagenesis
Sediment Diagenesis http://eps.mcgill.ca/~courses/c542/ SSdiedimen t Diagenes is Diagenesis refers to the sum of all the processes that bring about changes (e.g ., composition and texture) in a sediment or sedimentary rock subsequent to deposition in water. The processes may be physical, chemical, and/or biological in nature and may occur at any time subsequent to the arrival of a particle at the sediment‐water interface. The range of physical and chemical conditions included in diagenesis is 0 to 200oC, 1 to 2000 bars and water salinities from fresh water to concentrated brines. In fact, the range of diagenetic environments is potentially large and diagenesis can occur in any depositional or post‐depositional setting in which a sediment or rock may be placed by sedimentary or tectonic processes. This includes deep burial processes but excldludes more extensive hig h temperature or pressure metamorphic processes. Early diagenesis refers to changes occurring during burial up to a few hundred meters where elevated temperatures are not encountered (< 140oC) and where uplift above sea level does not occur, so that pore spaces of the sediment are continually filled with water. EElarly Diagenesi s 1. Physical effects: compaction. 2. Biological/physical/chemical influence of burrowing organisms: bioturbation and bioirrigation. 3. Formation of new minerals and modification of pre‐existing minerals. 4. Complete or partial dissolution of minerals. 5. Post‐depositional mobilization and migration of elements. 6. BtilBacterial ddtidegradation of organic matter. Physical effects and compaction (resulting from burial and overburden in the sediment column, most significant in fine-grained sediments – shale) Porosity = φ = volume of pore water/volume of total sediment EElarly Diagenesi s 1. -
MSA PRESIDENTIAL ADDRESS Metamorphism and the Evolution of Subduction on Earth
American Mineralogist, Volume 104, pages 1065–1082, 2019 MSA PRESIDENTIAL ADDRESS Metamorphism and the evolution of subduction on Earth MICHAEL BROWN1,* AND TIM JOHNSON2,3 1Laboratory for Crustal Petrology, Department of Geology, University of Maryland, College Park, Maryland 20742, U.S.A. Orcid 0000-0003-2187-616X 2School of Earth and Planetary Sciences, The Institute for Geoscience Research (TIGeR), Curtin University, GPO Box U1987, Perth, West Australia 6845, Australia. Orcid 0000-0001-8704-4396 3Center for Global Tectonics, State Key Laboratory for Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei Province, 430074, China ABSTRACT Subduction is a component of plate tectonics, which is widely accepted as having operated in a manner similar to the present-day back through the Phanerozoic Eon. However, whether Earth always had plate tectonics or, if not, when and how a globally linked network of narrow plate boundaries emerged are mat- ters of ongoing debate. Earth’s mantle may have been as much as 200–300 °C warmer in the Mesoarchean compared to the present day, which potentially required an alternative tectonic regime during part or all of the Archean Eon. Here we use a data set of the pressure (P), temperature (T), and age of metamorphic rocks from 564 localities that vary in age from the Paleoarchean to the Cenozoic to evaluate the petrogenesis and secular change of metamorphic rocks associated with subduction and collisional orogenesis at convergent plate boundaries. Based on the thermobaric ratio (T/P), metamorphic rocks are classified into three natural groups: high T/P type (T/P > 775 °C/GPa, mean T/P ~1105 °C/GPa), intermediate T/P type (T/P between 775 and 375 °C/GPa, mean T/P ~575 °C/GPa), and low T/P type (T/P < 375 °C/GPa, mean T/P ~255 °C/GPa). -
Part 629 – Glossary of Landform and Geologic Terms
Title 430 – National Soil Survey Handbook Part 629 – Glossary of Landform and Geologic Terms Subpart A – General Information 629.0 Definition and Purpose This glossary provides the NCSS soil survey program, soil scientists, and natural resource specialists with landform, geologic, and related terms and their definitions to— (1) Improve soil landscape description with a standard, single source landform and geologic glossary. (2) Enhance geomorphic content and clarity of soil map unit descriptions by use of accurate, defined terms. (3) Establish consistent geomorphic term usage in soil science and the National Cooperative Soil Survey (NCSS). (4) Provide standard geomorphic definitions for databases and soil survey technical publications. (5) Train soil scientists and related professionals in soils as landscape and geomorphic entities. 629.1 Responsibilities This glossary serves as the official NCSS reference for landform, geologic, and related terms. The staff of the National Soil Survey Center, located in Lincoln, NE, is responsible for maintaining and updating this glossary. Soil Science Division staff and NCSS participants are encouraged to propose additions and changes to the glossary for use in pedon descriptions, soil map unit descriptions, and soil survey publications. The Glossary of Geology (GG, 2005) serves as a major source for many glossary terms. The American Geologic Institute (AGI) granted the USDA Natural Resources Conservation Service (formerly the Soil Conservation Service) permission (in letters dated September 11, 1985, and September 22, 1993) to use existing definitions. Sources of, and modifications to, original definitions are explained immediately below. 629.2 Definitions A. Reference Codes Sources from which definitions were taken, whole or in part, are identified by a code (e.g., GG) following each definition. -
The Metamorphosis of Metamorphic Petrology
Downloaded from specialpapers.gsapubs.org on May 16, 2016 The Geological Society of America Special Paper 523 The metamorphosis of metamorphic petrology Frank S. Spear Department of Earth and Environmental Sciences, JRSC 1W19, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180-3590, USA David R.M. Pattison Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada John T. Cheney Department of Geology, Amherst College, Amherst, Massachusetts 01002, USA ABSTRACT The past half-century has seen an explosion in the breadth and depth of studies of metamorphic terranes and of the processes that shaped them. These developments have come from a number of different disciplines and have culminated in an unprece- dented understanding of the phase equilibria of natural systems, the mechanisms and rates of metamorphic processes, the relationship between lithospheric tecton- ics and metamorphism, and the evolution of Earth’s crust and lithospheric mantle. Experimental petrologists have experienced a golden age of systematic investigations of metamorphic mineral stabilities and reactions. This work has provided the basis for the quantifi cation of the pressure-temperature (P-T) conditions associated with various metamorphic facies and eventually led to the development of internally con- sistent databases of thermodynamic data on nearly all important crustal minerals. In parallel, the development of the thermodynamic theory of multicomponent, multi- phase complex systems underpinned development of the major methods of quantita- tive phase equilibrium analysis and P-T estimation used today: geothermobarometry, petrogenetic grids, and, most recently, isochemical phase diagrams. New analytical capabilities, in particular, the development of the electron micro- probe, played an enabling role by providing the means of analyzing small volumes of materials in different textural settings in intact rock samples. -
Petrology of the Metamorphic Rocks
Petrology of the metamorphic rocks Second Edition Roger Mason London UNWIN HYMAN Boston Sydney Wellington © R. Mason, 1990 This book is copyright under the Berne Convention. No reproduction without permission. All rights reserved. Published by the Academic Division of Unwin Hyman Ltd 15/17 Broadwick Street, London WIV IFP, UK Unwin Hyman Inc. 955 Massachusetts Avenue, Cambridge, MA 02139, USA Allen & Unwin (Australia) Ltd 8 Napier Street, North Sydney, NSW 2060, Australia Allen & Unwin (New Zealand) Ltd in association with the Port Nicholson Press Ltd Compusales Building, 75 Ghuznee Street, Wellington I, New Zealand First published in 1990 British Library Cataioguing in Publication Data Mason, Roger 1941- Petrology of the metamorphic rocks. - 2nd ed. I. Metamorphic rocks. Petrology I. Title 552.4 ISBN 978-0-04-552028-2 ISBN 978-94-010-9603-4 (eBook) DOI 10.1007/978-94-010-9603-4 Library of Congress Cataioging-in-Publication Data Mason, Roger, 1941- Petrology of the metamorphic rocks/Roger Mason. - 2nd ed. p. cm. Includes bibliographical references. 1. Rocks, Metamorphic. I. Title. QE475.A2M394 1990 552·.~c20 90-35106 CIP Typeset in 10 on 12 point Times by Computape (Pickering) Ltd, North Yorkshire Preface 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. -
Beachrock, in Schwartz, ML, Ed., Encyclopedia of Coastal Science
Turner, RJ. 2005. Beachrock, in Schwartz, ML, ed., Encyclopedia of Coastal Science. Kluwer Academic Publishers, The Netherlands. Pp. 183-186. BEACHROCK Formation and Distribution of Beachrock Beachrock is defined by Scoffin and Stoddart (1987, 401) as "the consolidated deposit that results from lithification by calcium carbonate of sediment in the intertidal and spray zones of mainly tropical coasts." Beachrock units form under a thin cover of sediment and generally overlie unconsolidated sand, although they may rest on any type of foundation. Maximum rates of subsurface beachrock cementation are thought to occur in the area of the beach that experiences the most wetting and drying - below the foreshore in the area of water table excursion between the neap low and high tide levels (Amieux et al, 1989; Higgins, 1994). Figure B49 shows a beachrock formation displaying typical attributes. Figure B49 Multiple unit beachrock exposure at barrio Rio Grande de Aguada, Puerto Rico. The sculpted morphology, development of a nearly vertical landward edge, and dark staining of outer surface by cyanobacteria indicate that this beachrock has experience extended exposure. Landward relief and imbricate morphology of beachrock units define shore- parallel runnels that impound seawater (photo R. Turner). There are a number of theories regarding the process of beach sand cementation. Different mechanisms of cementation appear to be responsible at different localities. The primary mechanisms proposed for the origin of beachrock cements are as follows: 1) -
Metamorphic Rocks
Metamorphism and metamorphic rocks GEOL115 Alexander Lusk Outline: • Metamorphic rocks – Defini>on and major types of metamorphism – Rock cycle • Metamorphic processes • Deformaon and development of a foliaon/ schistosity/cleavage • Progressive (prograde) metamorphic series • Environments of metamorphism • Metamorphic facies Metamorphic rocks If pre-exis>ng rocks (e.g. igneous, sedimentary, metamorphic) are buried within in the Earth, new minerals can grow in the solid rock through recrystallizaon and the rock can deform in response to tectonic forces. This rock may have started off as a sediment of mud or clay, which later become a sedimentary rock such as mudstone or shale … What minerals are present? Recall the rock cycle: Recall where different rock types form: Types of metamorphism Regional metamorphism: as rocks are buried deeper and deeper within the earth they are subject to increasingly higher pressures and temperatures, which result in recrystallization. The directed pressures (stresses) produce planar structures called foliation. Contact metamorphism: rocks within the crust that are intruded by magma are recrystallized by the magma’s high temperatures. These rocks are commonly not deformed (foliated). Processes involved: 1. Neomineralizaon – growth of new minerals replacing minerals that become unstable. 2. Grain growth – growth of new or exis>ng mineral grains. 3. Deformaon – creates a schistosity or foliaon defined by the orientaon of platy or elongate mineral grains. Neomineralizaon Porphyroblasts: Porphyroclasts: Grain growth: -
Sedimentary Rock Formation Models
Sedimentary Rock Formation Models 5.7 A Explore the processes that led to the formation of sedimentary rock and fossil fuels. The Formation Process Explained • Formation of these rocks is one of the important parts of the rock cycle. For millions of years, the process of deposition and formation of these rocks has been operational in changing the geological structure of earth and enriching it. Let us now see how sedimentary rocks are formed. Weathering The formation process begins with weathering of existent rock exposed to the elements of nature. Wind and water are the chisels and hammers that carve and sculpt the face of the Earth through the process of weathering. The igneous and metamorphic rocks are subjected to constant weathering by wind and water. These two elements of nature wear out rocks over a period of millions of years creating sediments and soil from weathered rocks. Other than this, sedimentation material is generated from the remnants of dying organisms. Transport of Sediments and Deposition These sediments generated through weathering are transported by the wind, rivers, glaciers and seas (in suspended form) to other places in the course of flow. They are finally deposited, layer over layer by these elements in some other place. Gravity, topographical structure and fluid forces decide the resting place of these sediments. Many layers of mineral, organics and chemical deposits accumulate together for years. Layers of different deposits called bedding features are created from them. Crystal formation may also occur in these conditions. Lithification (Compaction and Cementation) Over a period of time, as more and more layers are deposited, the process of lithification begins. -
Weathering Transportation Deposition Sediments Sedimantary Rocks
Weathering Transportation Deposition Uplift & exposure Sediments Igneous rocks (extrusive) Lithification Pyroclastic (Compaction and material Cementation) Consolidation Sedimantary rocks Igneous rocks (ıntrusion) Metamorphic Crystallization rocks Melting Prof.Dr.Kadir Dirik Lecture Notes Prof.Dr.Kadir Dirik Lecture Notes Sediment and Sedimentary Rocks The term sediment refers to (1) all solid particles of preexisting rocks yielded by mechanical and chemical weathering, (2) minerals derived from solutions containing materials dissolved during chemical weathering and (3) minerals extracted from sea water by organisms to build their shell. Sedimentary rock is simply any rock composed of sediments. 2 Prof.Dr.Kadir Dirik Lecture Notes Sedimentary rocks cover about two thirds of the continents and most of the seafloor, except spreading ridges. All rocks are important to understand the Earth history, but sedimentary rocks play a special role because they preserve evidence of surface processes responsible for them.By studying sedimentary rocks we can determine past distribution of streams, lakes, deserts, glaciers, and shorelines. They also make interferences about ancient climates and biosphere. In adition, some sediments and sedimentary rocks are themselves natural resources, or they are the host for resources such as petroleum and natural gas. Depositional Processes (Çökelme Süreçleri) Weathering & Erosion, Transportation, Deposition / Sedimentation and Diagenesis. Weathering & Erosion Weathering and erosion are the fundamental processes in the origin of sediment. During this process two types of sediments are produced: detrital sediments and chemical sediments. 3 Prof.Dr.Kadir Dirik Lecture Notes Ayrışma/bozunma erozyon Taşınma ve Çökelme/depolanma Gömülme ve taşlaşma 4 Prof.Dr.Kadir Dirik Lecture Notes Detrital Sediments. are all particles derived from any type of weathering. -
Relative Dating of Rock Sequences Rocks Tell Their Stories All That Remains Is for Us to Observe and Infer Their History. 1
Relative Dating of Rock Sequences Rocks Tell Their Stories All that remains is for us to observe and infer their history. Look at the 2 illustrations in this lesson which show several horizontally layered sedimentary rock layers, igneous intrusions and faults. They have been numbered and lettered for ease of reference. In this lesson we will tell the "story" of the rock sequences by observing certain characteristics: 1- The order in which the rock layers appear. 2- Erosional Surfaces 3- Unconformities If you need help with the submergence , emergence and unconformity issues, go to Submergence and Emergence of Rock Layers With Respect to Sea Level, look at the illustrations and read the captions. The Key: Be sure to look at the key before observing the series of illustrations. Notice that not only do symbols exist for sandstone, shale and conglomerate, but also for the loose sediments that will eventually lithify to become these rock types. Go On To Page 2 Let the Stories Begin! L. Immoor 2006 Geoteach.com 1 This is the "story" for Rock Sequence 1: 1- Submergence followed by Deposition and the Formation of layers 1 and 2 (the sandstone and limestone). 2- Emergence and Erosion of layer 2 (limestone). 3- Submergence followed by Deposition and the Formation of layer 3, (the shale) producing an unconformity with layer 2 (limestone). The unconformity is evidenced by the wavy, eroded top surface of a rock layer. 4- Igneous Intrusion A with resulting Contact Metamorphism of layers 1, 2 and 3 (the sandstone, limestone and shale). 5- Emergence and Erosion of layer 3 (shale) and Igneous Intrusion A.