Burial metamorphism overlaps, to some extent, with diagenesis, and grades into. Regional thermal metamorphism and deformation of the. Symmes gh, ferry jm 1992 the effect of whole rock mno content on the stability of garnet in pelitic schists during metamorphism. Metamorphism of greater and lesser himalayan rocks exposed in.
The change occurs primarily due to heat, pressure, and the introduction of chemically active fluids. Prograde polyphase regional metamorphism of pelitic rocks, nw of. Lecture notes petrology earth, atmospheric, and planetary. Metamorphism of basic and pelitic rocks at sulitjelma. Very lowgrade metamorphic evolution of pelitic rocks under. The chemical components and crystal structures of the minerals making up the rock may change even. Other zeolite minerals are analcime, clinoptilolite, heulandite, natrolite, phillipsite, and stilbite. This implies a large and pervasive hro influx during the initial stages of metamorphism. Petrogenesis of metamorphic rocks presents a large number of diagrams showing the stability relations among minerals and groups of minerals found in metamorphic rocks.
Regional metamorphism of pelitic rocks patna university. In these rocks the transitions from nonmetamorphic to very lowgrade and from very lowgrade to lowgrade metamorphic domains take place through the diagenetic zone, the anchizone and the epizone, each zone being characterized by specific values of the illite kubler index ki arkai et al. If the temperature of metamorphism is high enough for partial melting of the rock to occur, the. Preface this new edition of petrogenesis of metamorphic rocks has several completely revised chapters and all chapters have updated references and redrawn. Contact metamorphism of pelitic rocks in the skiddaw aureole, uk the zones determined on a textural basis prefer to use the sequential appearance of minerals and isograds to define zones but lowp isograds converge in pt skiddaw sequence of mineral development with grade is difficult to determine accurately. Metamorphism conference paper pdf available progressive metamorphism of pelitic rocks from greenschist to upper amphibolite facies in the area around kandra, saraikelakharsawan district, jharkhand. One or two of the minerals listed for mafic or calcareous or pelitic rocks in the appropriate facies may also be present.
The diagrams help to determine the pressure and temperature conditions under which a given set of metamorphic rocks may have. In the study of very low and lowgrade metamorphic rocks, maturation of organic matter and reaction progress, and. Chemical, mineralogical and structural adjustments of. 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. Following a common pattern, the intrusions are shallow, and the. Oct 25, 2000 barrovian metamorphism is the most commonly encountered.
Talc forms between biotite and chlorite along the mgrich side of the diagram. During regional metamorphism of pelitic rocks e,g, shale, a common sedimentary rock, rich in clay minerals alrich, typical metamorphic. Changes occur in the solid state because melting doesn t occur. Very lowgrade metamorphic evolution of pelitic rocks under high. Pdf metamorphism of pelitic alrich rocks researchgate. Metamorphic zones in pelitic rocks, and locations of diagnostic mineral assemblages.
Structure and petrology of pelitic schist in the fremont. In geology this refers to the changes in mineral assemblage and texture that result from subjecting a rock to pressures and temperatures different from those under which the rock originally formed. A fluidinclusion study of metamorphosed pelitic and. Rock can be heated by burial, exposure to igneous intrusions, or collision each of these can be associated with different pressures so metamorphism can rarely be due only to temperature the term stress implies direction, and is a more useful term than pressure, especially since metamorphic rocks record differential stress. Contact metamorphism in pelitic rocks on the island of kos greece. Metamorphism of basic and pelitic rocks at sulitjelma, norway. The fremont peak pendant is the largest of many small exposures of sur series metasedimentary rocks in the northern gabilan range which lies along the eastern edge of the central salinian block, california coast ranges. 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.
After chlorite breaks down the kyanite forms in many metapelites. These changes produce new minerals,new textures,and new structures within the rock body. Result of low temperature hydrothermal alteration andor metamorphism in the zeolite facies. Metamorphism of pelitic rocks during subduction produces chlorite sudoite, carpholite and chloritoid at relatively low pressure, and mgrich.
Progressive metamorphism of pelitic rocks from protolith to. Metamorphism conference paper pdf available progressive metamorphism of pelitic rocks from greenschist to upper amphibolite facies in the area around kandra. Prograde barrovian type of metamorphism of pelitic rocks around. Metamorphism in pelitic hornfels rocks is also discussed and migmatitic textures are illustrated. Sep 25, 2017 the word metamorphism comes from the greek. 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.
Kisch, chapter 5 mineralogy and petrology of burial diagenesis burial metamorphism and incipient metamorphism in clastic rocks, diagenesis in sediments and sedimentary rocks, 10. Abstract a complete barrovian sequence ranging from unmetamorphosed shales to sillimanitekfeldspar zone metapelitic gneisses crops out in a region. Maine, have been regionally metamorphosed to the biotite, garnet. Buchan facies series metamorphism is in northeastern scotland see map above in the dalradian series.
Contact metamorphism of pelitic rocks in the skiddaw aureole, uk the zones determined on a textural basis prefer to use the sequential appearance of minerals and isograds to define zones but lowp isograds converge in pt skiddaw sequence of mineral development with grade is. Pelitic rocks are slates or phyllites and typically contain chlorite, muscovite, quartz and albite. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. 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. Regional thermal metamorphism and deformation of the sitka. During metamorphism, new minerals grow at the expense of old minerals, andor the shape, size, and arrangement of grains in the rock may change. Rock metamorphism is primarily induced by largescale tectonic changes, processes that occur over very long time intervals, commonly 10 5 to 10 6. New minerals grow, but the rock does not appear to be metamorphosed. A process of change 1 metamorphic rock forms from a preexisting rock or protolith. At a higher grade the chlbt tieline flips to the tlccld tieline c. The metamorphic rocks exposed near juneau, alaska, are part of the western. Progressive metamorphism of pelitic rocks from protolith to granulite.
The diagrams help to determine the pressure and temperature conditions under which a given set of metamorphic rocks may have formed. Pelites are derived from clay rich sediments and are of. Metamorphic petrology 3 metamorphism of pelitic rocks minerals and isograds. This question hasnt been solved yet ask an expert ask an expert ask an expert done loading. The intensity of contact metamorphism decreases from the innermost. Metamorphic rocks and processes metamorphism comes from the greek words meta change morphe form metamorphic rocks form by solidstate no melting transformation of preexisting rock by processes that take place beneath earths surface.
The zone where contact metamorphism occurs is called the contact aureole, while the products of such metamorphism are called contact rocks. If the temperature of metamorphism is high enough for partial melting of the rock to occur, the changes would still be called metamorphism until the melt is separated from its. Sep 23, 2016 when sedimentary rocks are buried to depths of several hundred meters, temperatures greater than 300oc may develop in the absence of differential stress. Overview of metamorphism and tectonics uc santa barbara. Interaction between metamorphism and deformation part 12. Mineral associations and localities of samples of pelitic and semipelitic rocks. Although begin as humble mud, metapelites represent a distinguished family of metamorphic rocks, because. Rock metamorphism an overview sciencedirect topics. Much information on metamorphism of these rock types has already been given when describing individual units, so this section is focussed on providing a synthesis. Metamorphism at high temperatures and low to medium pressures is widespread in many orogenic belts. The driving forces for metamorphism are changes in temperature,pressure,and composition of pore fluids. It represents a common type of regional pelitic orogenic metamorphism. Their high al content leads to a highpercentage of micasin the resulting metamorphic rock. Two periods of folding and three periods of metamorphism were identified in pelitic schist.
It occurs in intense tectonic conditions associated with volcanic arcs, and major mountain building. Metamorphism of pelitic rocks during subduction produces chlorite sudoite, carpholite and chloritoid at relatively low pressure, and mgrich garnet, talc, kyanite, andor sirich white mica at. Their high al content leads to a high percentage of micas in the resulting metamorphic rock. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience. Progressive metamorphism of pelitic rocks from greenschist to upper amphibolite facies in the area around kandra, saraikelakharsawan district, jharkhand. In many common rock types, such as marine pelites and carbonates, no diagnostic minerals or mineral. Metamorphism of greater and lesser himalayan rocks.
Introductory phase equilibria and thermodynamics part 5. Prograde polyphase regional metamorphism of pelitic rocks, nw. Barrow 1893 mapped metamorphic zones in pelitic rocks based on mineral assemblages he observed in a small part the area. Here the pelitic rocks in the mapped zones contain the following mineral assemblages. Greenschist facies to amphibolite facies conditions are indicated by the formation of the index minerals chloritoid, garnet, staurolite and kyanite in pelitic rocks. Metamorphism of pelitic rocks metapelites springerlink. The thickness of the aureole ranges from the millimetre to the kilometrescale. Pelitic rocks are fine grained mudstones, siltstones and shalesthat contain a high percentage of clays, with lesser quartz andvariable amounts of calcite.
Metamorphic petrology 2 metamorphic facies heat flow and heat production in crust. Very lowgrade metamorphic evolution of pelitic rocks. In the late 1800s and early 1900s, george barrow discovered the classic barroviantype metamorphic sequence in the southeastern scottish highlands. This powerpoint presentation includes 30 slides discussing metamorphism in pelitic rocks. Effected by lower paleozoic caledonian orogeny barrow recognized metamorphism was progressive. Metamorphism, fluid flow and partial melting in pelitic rocks. The precursors to these hightemperature metamorphic.
The progressive nature of metamorphism 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. Metamorphic rocks presentation free download as powerpoint presentation. Apr 18, 2012 buchan facies series metamorphism is in northeastern scotland see map above in the dalradian series. Progressive metamorphism of pelitic rocks from protolith to granulite facies, dutchess county, new york, usa. Metamorphic petrology 4 pelites the akfm system continuous and discontinuous reactions. Progressive metamorphism of pelitic and quartzofeldspathic rocks in. Contact metamorphism of pelitic rocks in the skiddaw aureole, uk ordovician skiddaw slates in the english lake district are intruded by several granite and granodiorite bodies. Metamorphism of greater and lesser himalayan rocks exposed in the modi khola valley, central nepal aaron j. Prograde polyphase regional metamorphism of pelitic rocks, nw of jamshedpur, eastern india.
Introduction previous geologic studies on baranof island loney and others, 1975, p. This resource is part of the teaching petrology collection. Thickness 1015 km thick some structural thickening. Orthopyroxene occurs in pelitic and quartzofeldspathic rocks only at the very highest grades of contact and regional metamorphism, grades that may not be reached prior to melting in many instances. Jun 01, 1986 conclusions the pelitic and basic rocks discussed in this paper show mineralogical changes characteristic of prograde regional metamorphism under greenschist facies and amphibolite facies conditions, the major mineralogi cal change in pelitic rocks is the formation of garnet and biotite at the expense of muscovite, chlorite and carbonate. Regional metamorphism of pelitic rocks pelites are derived from clay rich sediments and are of significant importance because they develop wide range of distinctive. Lower paleozoic pelitic rocks in the errol quadrangle, northern new hampshire and. Pelitic rocks are slates or phyllites and typically. Petrologic characterization of pelitic schists in the western. The protoliths for pelitic rocks are shales aluminous rocks, not sandstones quartzofeldspathic rocks here are the stability fields of common pelitic minerals. 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%. Differential stress aligns the micas, so a pronouncedfoliationis developed. A more precise location is presented on a geologic map by guidotti 1963. Metamorphic petrology 5 metamorphism of mafic rocks.
Progressive metamorphism of pelitic rocks from protolith. He observed that as a pelitic rock undergoes higher pressures and temperatures, its mineral assemblage changes from predominantly chlorite to biotite to. The pelitic rocks in the bryant pond area have been metamorphosed to the sillimanite and sillimanitepotash feldspar grades of metamorphism and an isograd fig. Regional metamorphism of pelitic rocks pelitic rocks are fine grained mudstones, siltstones and shales that contain a high percentage of clays, with lesser quartz and variable amounts of calcite.
Metamorphism, fluid flow and partial melting in pelitic. Prograde polyphase regional metamorphism of pelitic rocks. Abstract the effects of tertiary alpine metamorphism on pelitic mesozoic cover rocks have been studied along a cross. Fingerprint dive into the research topics of progressive metamorphism of pelitic rocks from protolith to granulite facies, dutchess county, new york, usa. Alpine metamorphism of pelitic schists in the nufenen pass. Petrogenesis of metamorphic rocks kurt bucher springer. Greenschist facies to amphibolite facies conditions are indicated by the formation of the index minerals chloritoid, garnet, staurolite and kyanite in.
A thorough presentation on characteristics and description of all main types of metamorphic rocks. Download free pdf progressive metamorphism of pelitic rocks from protolith to granulite facies, dutchess county, new york, usa. Metamorphic rocks metamorphic rocks are classified on the basis of texture and composition either mineralogical or chemical unlike igneous rocks, which have been plagued by a proliferation of local and specific names, metamorphic rock names are surprisingly simple and flexible may choose some prefixtype modifiers to attach. The term was earlier used by geologists to describe a clayrich, finegrained clastic sediment or sedimentary rock, i. Pdf progressive metamorphism of pelitic rocks from.
Lecture eight metamorphism of pelitic rocks metapelites. Early eastwest trending, isoclinal folding accompanied by sillimanite. Hornfelses are tough, and tend to splinter when broken. Structure and petrology of pelitic schist in the fremont peak. Contact metamorphism of pelitic, psammitic and calcareous. Pelitic rocks are fine grained mudstones, siltstones and shales that contain a high percentage of clays, with lesser quartz and variable amounts of calcite. The presentation uses akf diagrams to describe barrovian zones of metamorphism in metapelites.
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