Metamorphic rock metamorphic rock metamorphic facies. Metamorphism is the change of minerals or geologic texture distinct arrangement of minerals in preexisting rocks, without the protolith melting into liquid magma a solidstate change. Pdf progressive metamorphism of pelitic rocks from the. The diagrams help to determine the pressure and temperature conditions under which a given set of metamorphic rocks. Aphebian metapelites and quartzofeldspathic rocks from the grenville province south of the labrador trough display progressive changes in mineral assemblages as a result of grenvillian metamorphism, consistent with variation in grade from greenschist to upper amphibolite facies. Metamorphism of mafic rocks first evident in the greenschist facies, which correlates with the chlorite and biotite zones of the associated pelitic rocks ftypical minerals include chlorite, albite, actinolite, epidote, quartz, and possibly calcite, biotite, or stilpnomelane fchlorite, actinolite, and. Metamorphic petrologists studying contact metamorphism early in the 20th century introduced the idea of metamorphic facies part of a rock or group of rocks that differs from the whole formation to correlate metamorphic events. Mesoproterozoic highgrade metamorphism in pelitic rocks. A rock at a high metamorphic grade probably progressed through a sequence of mineral assemblages rather than hopping directly from an unmetamorphosed rock to the metamorphic rock. Gnnnn, department oj geol,ogy, uniaersity oj minnesota, dulwth, minn,esota.
The approximate location of the pelitic zones of barrovian metamorphism are included for comparison. Pelitic rocks exposed to contact metamorphism what is a metamorphic facies and what is the concept used for. Pdf the study area belongs to the singhbhum metamorphic belt of jharkhand, situated in the eastern part of india. Winter 2010 an introduction to igneous and metamorphic petrology. Petrogenesis of metamorphic rocks presents a large number of diagrams showing the stability relations among minerals and groups of minerals found in metamorphic rocks. Progressive metamorphism of pelitic rocks from protolith. Winter, chapter 28 metapelite mineralogy fine alkrich phyllosilicates, such as clays montmorillonite, kaolinite, or smectite, fine white micas sericite, paragonite, or phengite and chlorite the phyllosilicates may compose more than 50% of the original sediment fine quartz constitutes another 1030%.
Pdf prograde polyphase regional metamorphism of pelitic. Burial of rocks in the earths crust results in progressive metamorphism as the rocks are subjected to increasing pressure and temperature. Many distinct metamorphic minerals are found in meta pelitic rocks e. Metapelites, are metamorphic rocks, which derived from contact or regional metamorphism of shale or mudstones clay rich sediments. Pdf progressive metamorphism of pelitic rocks from the pan. Graham borradaile, in understanding geology through maps, 2014. Maine, have been regionally metamorphosed to the biotite, garnet. Prograde polyphase regional metamorphism of pelitic rocks, nw of jamshedpur. Contact metamorphic rocks recommendations by the iugs subcommission on the systematics of metamorphic rocks. Constraints on the timing of fluid infiltration during regional metamorphism. Meta t change, morph form, so metamorphism means to change form. Barrovian metamorphism is the most commonly encountered. A more precise location is presented on a geologic map by guidotti 1963. Guroorrr, department of geologicol sci,ences, ll niv er s ity of c alif or ni a, d aai s, c olij or ni a.
The pressure experienced by a rock during metamorphism is due primarily to the weight of the overlying rocks i. Pelite facies series and the temperatures and pressures of. If retrograde metamorphism were a common process then upon uplift and unroofing metamorphic rocks would progressively return to mineral assemblages stable at lower pressures and temperatures. The pelitic rocks in the bryant pond area have been metamorphosed to the sillimanite and sillimanitepotash feldspar grades of metamorphism and an isograd. A fluidinclusion study of metamorphosed pelitic and. Progressive metamorphism of pelitic rocks from protolith to granulite facies, dutchess county, new york, usa. A regional study of metamorphosed pelitic rocks in. The lab is designed to be completed in two 3hour lab sessions, at the end of which the students will be able to. Metamorphism of pelitic rocks metapelites springerlink.
These keywords were added by machine and not by the authors. Metamorphism of the pelitic rocks of the snyder group in the contact aureole of the kiglapait layered intrusion, labrador. Metamorphic rocks are sedimentary or igneous rocks that have been changed in mineralogy and texture, usually at great depth due to the effects of any combination of heat, pressure, strain, and aggressive fluid interaction. Metamorphic mineral assemblages of slightly calcic pelitic. Apr 22, 2011 whitney dl, mechum ta, kuehner sm, dilek yr 1996 progressive metamorphism of pelitic rocks from protolith to granulite facies, dutchess county, new york, usa. Pdf progressive metamorphism of pelitic rocks from. Callegari, department of science, mineralogy and petrology, university of torino, italy. Freely browse and use ocw materials at your own pace. This new edition of petrogenesis of metamorphic rocks has several completely revised chapters and all chapters have updated references and redrawn. If the temperature of metamorphism is high enough for partial melting of the rock to occur, the.
We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Due to the very common presence of smectite in early diagenesis of pelitic sediments and. Prograde polyphase regional metamorphism of pelitic rocks, nw of jamshedpur, eastern india. We have already discussed the facies concept and done a lab on mafic rocks by the time we get to this assignment. Changes produced by surface conditions such as compaction are usually excluded. Metamorphic facies an overview sciencedirect topics. Introductory phase equilibria and thermodynamics part 5.
Metamorphism of the pelitic rocks of the snyder group in the. Symmes gh, ferry jm 1995 metamorphism, fluid flow and partial melting in pelitic rocks from the onawa contact aureole, central maine, usa. Petrogenesis of metamorphic rocks kurt bucher springer. Progressive metamorphism of pelitic and quartzofeldspathic rocks in the grenville province of western labrador tectonic implications of bathozone 6 assemblages. View enhanced pdf access article on wiley online library html view. Progressive metamorphism of pelitic and quartzofeldspathic rocks in the grenville province of western labrador tectonic implications of bathozone 6 assemblages t. Again, this discussion and classification applies only to rocks that are not produced by highstrain metamorphism. The presentation uses akf diagrams to describe barrovian zones of metamorphism in metapelites. Metamorphism the process of changes in preexisting rocks topic 2. Prograde metamorphic sequence of ree minerals in pelitic rocks of the central alps. The disposition of regional metamorphic zones and minerals in pelitic rocks is shown in fig. Very lowgrade metamorphic evolution of pelitic rocks under. Estimating pressure and temperature of metamorphism.
Igneous and metamorphic petrology flashcards quizlet. Barrow 1893 mapped metamorphic zones in pelitic rocks based on mineral assemblages he observed in a small part the area. This process is experimental and the keywords may be updated as the learning algorithm improves. Metamorphism of the pelitic rocks of the snyder group in. Highlevel metamorphism of pelitic rocks in northern new hampshire jouu c. Lightning metamorphism is a type of metamorphism of local extent that is due to a strike of lightning. Typical mineral changes that take place in metabasic rocks during progressive metamorphism in the medium pt facies series. The standard scientific notation for pressure is expressed in pascals or megapascals 1 pascal is equivalent to 10 bars. Metamorphism of mafic rocks first evident in the greenschist facies, which correlates with the chlorite and biotite zones of the associated pelitic rocks ftypical minerals include chlorite, albite, actinolite, epidote, quartz, and possibly calcite, biotite, or stilpnomelane fchlorite, actinolite, and epidote impart the green. Prograde polyphase regional metamorphism of pelitic rocks, nw. This lab assignment helps students to develop a detailed understanding of afm diagrams and how they relate to pressuretemperature conditions of metamorphism of pelitic rocks.
The mineral assemblages from metamorphosed slightly calcic pelitic rocks of the taconic range in southwestern massachusetts and adjacent areas of connecticut and new york were studied petrographically and chemically. Metamorphism in pelitic hornfels rocks is also discussed and migmatitic textures are illustrated. Lecture notes petrology earth, atmospheric, and planetary. It occurs in intense tectonic conditions associated with volcanic arcs, and major mountain building. Pelitic rocks are slates or phyllites and typically. Petrologic characterization of pelitic schists in the western. Winter 2001 an introduction to igneous and metamorphic petrology.
Prograde polyphase regional metamorphism of pelitic rocks. The pelitic rocks in the bryant pond area have been metamorphosed to the sillimanite and sillimanitepotash feldspar grades of metamorphism and an isograd fig. The study group was also asked to consider metamorphism associated with other localised heat sources, such as combustion metamorphism and ligthning strikes. Metamorphism of pelitic rocks chapter 16 essentials of. These can range from textures similar to the original protolith at low grades of metamorphism, to textures that are purely produced during metamorphism and leave the rock with little resemblance to the original protolith. Moreover, compositions of coexisting minerals show regular variation with imposed. Metamorphism and zircon upb dating of highpressure. The most important agents of metamorphism include temperature, pressure, and fluids.
Implication for the extension of the kibaran intracontinental basins to tanzania author links open overlay panel nelson boniface b volker schenk a peter appel a. Interaction between metamorphism and deformation part 12. The protoliths for pelitic rocks are shales aluminous rocks, not sandstones quartzofeldspathic rocks here are the stability fields of common pelitic minerals. For example, staurolitebearing assemblages in pelitic rocks develop in the amphibolite facies, and thus are consistent with hornblendeplagioclase assemblages but not actinolitechlorite assemblages in interlayered mafic rocks. Applied geology, doctor harisingh gour vishwavidyalaya a central university, sagar. Metamorphism, fluid flow and partial melting in pelitic rocks. Field, petrologic and geochemical data were used to characterize fluid infiltration and partial melting during metamorphism of pelitic rocks in the contact aureole of the onawa pluton, central maine, usa.
Instructor resource file download the work is protected by local and international laws and is provided solely for the use of instructors in teaching their courses and assessing student learning. Quantifying the tectonometamorphic evolution of pelitic rocks from a wide range of tectonic settings. Using combinations of reactions that have likely taken place during metamorphism, petrologists have been able over the years to determine the pressure and temperature of metamorphism in a variety of rocks, and in so doing have been able to place constraints on the fields of temperature and. Pdf progressive metamorphism of pelitic rocks from protolith to. Pelitic rocks are slates or phyllites and typically contain chlorite, muscovite, quartz and albite. All chapters of part ii of the book have been rewritten.
The very lowgrade metamorphism has received limited attention, focusing on the determination of mineral assemblage stability fields and the mapping of mineral isograds black, 1975, 1977. Progressive metamorphism of pelitic and quartzofeldspathic. Progressive metamorphism of pelitic rocks from the panafrican kaoko belt, nw namibia. This area is characterised by a thick sequence of medium to high grade metamorphic rocks such as biotitechlorite schists, garnetmica schist. Barrow focused in on pelitic rocks and mapped using index minerals. Petrologic characterization of pelitic schists in the western metamorphic belt, coast plutonicmetamor phic complex, near juneau, southeastern alaska i by glen r. Given that metamorphic reactions are more rapid with rising than with falling temperature, metamorphic mineral assemblages may record the highest pt regime to which rocks have been subjected. This powerpoint presentation includes 30 slides discussing metamorphism in pelitic rocks. The hp pelitic rocks are of particular significance in understanding the tectonic setting and processes of the prydz belt, because only plate tectonic processes involving subduction and continentcontinent collision can bring the sedimentary precursors of pelitic rocks into a lower crustal depth where they experience hp metamorphism anderson et.
Yet, high grade metamorphic rocks are common at the surface of the earth and usually show only minor retrograde minerals. Barrovian metamorphism is widely found across time and space on all parts of the earth, and produces the most common metamorphic rocks. These rocks vary in metamorphic grade from those below the chloritoid zone through the chloritoid and garnet zones into the kyanitestaurolite zone. The concept was first defined in 1914 by a finnish petrologist, pentti eelis eskola, as any rock of a.
Chapter 7 metamorphism and metamorphic rock flashcards. Sep 23, 2016 metamorphism and types of metamorphism 1. Mesoproterozoic highgrade metamorphism in pelitic rocks of the northwestern ubendian belt. Contrib mineral petrol amphibolite facies contact aureole pelitic rock prograde metamorphism. Lower paleozoic pelitic rocks in the errol quadrangle, northern new hampshire and. This resource is part of the teaching petrology collection. Combustion metamorphism is a type of metamorphism of local extent produced by the spontaneous combustion of naturally occurring substances such as bituminous rocks, coal or oil. The term was earlier used by geologists to describe a clayrich, finegrained clastic sediment or sedimentary rock, i. Metapelites are probably the most distinguished family of metamorphic rocks. Process of mineralogical and structural textural changes of rocks in the.
Find materials for this course in the pages linked along the left. Lecture eight metamorphism of pelitic rocks metapelites 1 lecture eight metamorphism of pelitic rocks metapelites part i 2 what is the metapelites. The change occurs primarily due to heat, pressure, and the introduction of chemically active fluids. Typical metapelites include wellknown metamorphic rocks such as, for example. Also, the chapters introduction and grade have undergone several major changes. For each of the thin sections in this lab please write 12 paragraphs of rock.
Metamorphism of the pelitic schists in the bryant pond quadrangle, maine cnanrbs v. The mineral assemblage present in a pelitic rock gives qualitative but fairly accurate information on the peak metamorphic conditions the rock has experienced. Metamorphism, mineralogical and structural adjustments of solid rocks to physical and chemical conditions differing from those under which the rocks originally formed. Pdf progressive metamorphism of pelitic rocks from greenschist to. Okrusch 431 barrovian and buchan type metamorphism in the panafrican kaoko belt, namibia. Lecture notes metamorphism introduction metamorphism is a change of form that includes the growth of new minerals, typically in response to a rise in temperature and normally without the involvement of a magma. Pelitic rocks read chapter 3 of an introduction to metamorphic petrology by bruce yardley or chapter 28 of igneous and metamorphic petrology by john winter. Developed for an introductorylevel physical geology course.
Pdf prograde polyphase regional metamorphism of pelitic rocks. Quantifying the tectonometamorphic evolution of pelitic. Mode of emplacement forceful emplacement vs magmatic stoping. Attikamagen formation at the base of the knob lake. Close this message to accept cookies or find out how to manage your cookie settings. Review of the basic processes processes and products of metamorphism.
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