Mylonite finely ground, crushed rock formed by the movement of rock. The formation of mylonites fault rocks is complex and involves successive stages of deformation, recovery, and recrystallization. The mylonite, is the central part of the shear zone where deformation is the most intense. The permeability plugging tester ppt is a modification of the standard 500ml hthp filter press. This process involves nearly complete pulverisation of the parent rock so the original minerals are almost completely broken down and recrystallise as. Classification intrusive igneous rocks formed from the solidification of magma below ground extrusive igneous rocks formed from the solidification of lava above.
Thanks to our advanced conversion technology the quality of the output will be exactly the same as if the file was. Mylonite is a finegrained, compact metamorphic rock produced by dynamic recrystallization of. Mylonites a mylonite is a foliated and usually lineated rock that shows evidence for strong ductile deformation fig. The snake range has spectacular exposures of footwall mylonites, the detachment fault, overlying brittle fault block mosaics and the inverted deposits of miocene sedimentary basins. It is the main source of many nonfuel mineral resources. 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. Mylonites are rocks that have undergone modification of original textures by predominantly plastic flow due to dynamic recystallization. Formation of mylonites occur in strikeslip, extensional or compressional regimes, and are. The attitude of a linear structure is described by its, which is the. Igneous description forms the bulk of the earths crust. Model for a simple, planar fault style of faulting, but by dating the sediments, you can tell the age of the fault since sediments were deposited during faulting as well as the slip rates on the fault. Pdf a study of mylonites from parts of the salemattur. Add sound effects to a presentation course goals insert sound files and select how each one should start and stop. Grain size reduction typically occurs in the rocks, and a range of rocks commonly referred to as mylonites and cataclasites is formed.
Pdf initiation of cataclastic flow in a mylonite zone. Structural ore controls in the cariboo 093ah, cassiar. Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or. Type ii sc mylonites described here have widespread occurrence in quartzmica rocks involved in zones of intense noncoaxial laminar. Our knowledge of rock physics has significantly improved 2 over the last 30 years, mainly through experimental studies, providing new insights on earth deformation and dynamics. Mylonite mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism. The strain gradients from mylonite to undeformed rock are criteria to distinguish large.
The develop ment of mylonite microstructures and fabrics are discussed from this point of. Charles lapworths mylonites scottish journal of geology. Ductile shear zones generally record a noncoaxial deformation and may range from the grain scale to the scale of a few hundreds of kilometres in length and a few kilometres in width. They are usually finegrained, sometimes glassy, that are streaky or layered, with the layers and streaks having been drawn out by ductile shear. Hydrothermal fault breccia fault melt mylonites undeformed granite deformed young mountainsactive fault basin and range province.
It may be used in the field or in a laboratory environment. A study of mylonites from parts of the salemattur shear zone tamil nadu and its tectonic implications article pdf available in journal of the geological society of india 751. The instrument is useful for performing filtration tests on plugging materials without the interference of. Moine thrust zone in the eriboll area together with a cataclasite sequence.
An early origin of the eureka thrust is emphasized by. During deformation, pressure solution may contribute to fabric development, but deformation processes are basically mechanical in nature. Amongst many others, we do support pdf, pptx, ppt, odp. Mylonite is a finegrained, compact metamorphic rock produced by dynamic recrystallization of the constituent minerals resulting in a reduction of the grain size of the rock. Dislocation metamorphism is a type of metamorphism of local extent, associated with fault zones or shear zones. Recognize the different types of metamorphism, the processes that cause them, and the environments in which they occur. Tectonites tectonites are deformed rocks, the fabric of which is due to the systematic movement of the individual units under a common external force. The formation of mylonites occur at depth, below brittle faults, in continental and oceanic crust.
It is a 25 km wide corridor of granulite to lower greenschist facies mylonites and cataclastic fault rocks developed in the deepseated parts. The strain gradients from mylonite to undeformed rock are criteria to. Cloudconvert is a online document and presentation converter. Mylonites are partially recrystallised rocks with a pronounced foliation that are produced by intense shearing during largescale movements along faults and thrusts. Mylonites are cataclastic metamorphic rocks that are produced along shear zones deep in the crust. Mylonites article about mylonites by the free dictionary. In general, metamorphic rocks do not drastically change chemical.
In this section we will look at the most highly strained rocks in the lithosphere those found in shear zones. Mylonites form in ductile shear zones where there is significant strain. Plumes of volcanic ash can be seen above the remote south sandwich islands south atlantic ocean in this falsecolor image captured 29 september 2016 by the moderate resolution imaging spectroradiometer modis on nasas aqua satellite. In the mylonitic core, where c and s are subparallel, a new. Shear zone deformation in planar zones that accommodate movment of relatively rigid. Shear zonesmylonites by abzal alpysbayev bsc petroleum geology. Mylonites can have many different mineralogical compositions. Describe how metamorphic rocks are produced by the action of heat, pressure, and fluids on preexisting parent rocks over the course of time. When i left imperial college to take up a postdoctoral fellowship at the university of birmingham, the late professor john sutton pointed out that although lapworth had introduced the term mylonite and the process of mylonitization lapworth 1885, 1886, he had given few petrographical details and no illustration of his specimens.
These features are produced due to friction of the blocks on either side of the fault plane and include features like slickenside, grooves, drag or fluccan i. 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. Set up a slide element so that it triggers the sound. This field trip is a rare opportunity to learn more about crustal scale processes and extensional fault systems as. The bgc s comprises amphibolite facies gneisses with migmatites, schists, metasedimentary intrusions and plutons of synorogenic granite. Conditions of microfracturing in the southwestern adirondacks by fluid inclusion analysis johnluke henriquez, dr.
Faults the eureka thrust defines the western limit of the barkerville subterrane, and accommodates obduction of the quesnellia terrane onto the margin of ancestral north america fig. Impact metamorphism is a type of metamorphism of local extent caused by the passage of a. Lineation is one of the most significant fabric elements and it should be included in all complete structure maps. Scribd is the worlds largest social reading and publishing site. The mylonites which form in ductile shear zones are the softened medium. Dislocation glide is the fundamental process of deformation at high strain rates, by which mylonites flow. The different rock types produced by dynamic metamorphism vary with depth from the surface as, with increasing depth, both the surrounding pressure and temperature increase. Shear zones and deformation mechanisms introduction. Foliations, lineations, and latticepreferred orientation lpo. John sutton suggested that the material might still be in. Rock physics is needed to characterize reservoirs imaged by geophysical data.
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