Spelling suggestions: "subject:"metamorphic""
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Archaeometrical Study On Marble ForgerySongul, Gunes 01 July 2012 (has links) (PDF)
This thesis focuses on the detection of marble sculpture forgery made of cultured marble. Cultured marble is a mixture of marble dust, polyester and accelerators. Thus chemical analysis of cultured marble would give declined levels of calcium when compared to authentic sculptures. Since sample removal is a problem when dealing with archaeological heritage, the instrument used was portable X-Ray Fluorescence device which provides in situ analysis of the samples. Device has been used to analyze six authentic and four forgery sculptures. Seven of the sculptures were provided by Anatolian Civilizations Museum and three of them were provided by a sculpture workshop, Ak
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BEDROCK GEOLOGIC MAPPING AND STRUCTURAL ANALYSIS OF THE WESTERN HALF OF THE PETERSHAM QUADRANGLE, CENTRAL MASSACHUSETTS: FURTHER TESTS OF THE MODEL FOR MIDDLE TO LATE PALEOZOIC DUCTILE TRANSPRESSION, VERTICAL EXTRUSION, AND LATERAL ESCAPE IN THE NORTHERN APPALACHIANSRohrer, Lucas P. 01 January 2015 (has links)
Bedrock mapping, structural analysis, and geochronology reveal the distribution of lithologies and timing of metamorphism and deformation in the western half of the Petersham 7.5’ quadrangle, western Massachusetts. Underlying lithologies are: (from west to east) the Ordovician Monson granitic orthogneiss, Silurian Rangeley migmatitic paragneiss, and Late Devonian (357 Ma) Hardwick tonalitic orthogneiss. Their tightly folded contacts strike north to south. The 361 Ma, unfoliated, strike-parallel Nichewaug quartz-diorite (10-100 m wide) intrusion spans the map area within the Rangeley. Evidence for vertical and lateral extrusion/escape of the Monson orthogneiss, as observed in the Palmer MA area, is absent. Instead, petrofabrics (foliations and lineations) indicate E-W shortening and N-S stretching concentrated within the Rangeley Fm. and orthogneiss margins. Asymmetric structures at the Rangeley-Hardwick contact indicate localized sinistral displacement parallel to unit boundaries and tectonic fabrics. U-Th-Pb chemical age dating of Rangeley monazite revealed three precise age populations (1 = 344 Ma; 3 = 377 Ma; 4 = 405 Ma) and one broad population divided into two subpopulations: 2b (~370 Ma) and 2a (~ 360 Ma). The similarity in age between tonalitic/dioritic magmatism and monazite growth in the Rangeley suggests regional metamorphism was driven by magmatic heat input from latest Devonian/earliest Carboniferous plutonism.
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Implications of amazonite to sulfide-silicate equilibriaStevenson, Ross Kelley. January 1985 (has links)
No description available.
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Variable structural style, stratigraphy, total strain and metamorphism adjacent to the Purcell thrust, near Blackman Creek, B.C.Leonard, Richard. January 1985 (has links)
No description available.
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Structures and metamorphism of Ptarmigan Creek area, Selwyn Range, B.C.Forest, Richard C. January 1985 (has links)
No description available.
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PETROFABRIC AND GEOCHEMICAL ANALYSIS OF THE GREAT SMOKY -- SNOWBIRD GROUP CONTACT, WESTERN BLUE RIDGE, NORTH CAROLINA AND TENNESSEEClemons, Kristopher M. 01 January 2006 (has links)
Detailed structural and petrographic analysis of the Greenbrier Fault (GBF) reveal different fold and fabric styles and generations preserved in the Great Smoky Group (GSG) hanging wall and Snowbird Group (SG) footwall. Four planar fabrics (S0, S1, S2, and S3) are completely overprinted within meters of the contact by shear zone-related fabrics. Bedding (S0) is defined by planar laminations in the SG siltstones. S1 is weak, not associated with folding of S0, and defined locally by sub-parallel alignment of biotite. S2 (slaty cleavage) is deflected into a disjunctive planar (in GSG) or continuous planar (in SG) S3 foliation characterized by mica formation and dynamic recrystallization of quartz. Metamorphic microstructures indicate lower greenschist to upper amphibolite facies Taconian metamorphism is syn- to post-S2, and pre-S3. Local lower greenschist facies retrograde metamorphism precedes S3 formation. A meter scale, ductile mesoscopic shear zone in SG at the GSG-SG contact is characterized by S/C fabric; this is the youngest deformational event and postdates retrograde mineral assemblages indicating postmetamorphic motion along the contact. Premetamorphic fault fabrics indicative of GSG thrusting onto the SG were absent or completely reconstituted during metamorphism and deformation. The Metcalf phyllite and Pigeon siltstone were also compared to test the hypothesis that the Metcalf phyllite is tectonized Pigeon siltstone. Major and trace element abundances are similar between the lithologies, with the exception of depletion of Ca, Na and Zr in the Metcalf. The system appears to have been open with respect to these elements. It is concluded that the Metcalf phyllite is the tectonized equivalent of the Pigeon siltstone based on lateral continuity, the strong macroscopic and microscopic resemblance of weakly deformed Metcalf to the Pigeon, similar mean values and ranges in major, minor, and trace elements, and identical rock densities.
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Metamorphic studies in the south-east Tauern window, AustriaDroop, Giles T. R. January 1979 (has links)
Detailed structural and mineralogical mapping was undertaken in an area of 130 square kilometres within the Pennine Zone of the south-east Tauern Window, the Eastern Alps. A coherent tectono-metamorphic history is established for this area. Three pre-Alpine metamorphic events are recognised. The Alpine history involves two discrete phases of intense penetrative deformation which occurred under conditions of rising temperature, a widespread phase of thermal crystallisation at 35-40 mybp representing the attainment of maximum temperatures, and a minor post-metamorphic phase of deformation. The regional tectonic significance of this sequence is discussed. The spatial variation in Alpine peak metamorphic conditions is examined in terms of the distribution of mineral zones and isograds in metapelites. Staurolite+biotite assemblages were developed at low structural levels, and chloritoid+biotite assemblages along a thin wedge-shaped zone. Barrovian and Stonehavian facies series are both represented. Oxygen isotope studies on whole-rocks and mineral separates suggest that widespread circulation of metamorphic fluids did not occur during Alpine metamorphism. Thermodynamic calculations indicate that metamorphic conditions during the Alpine thermal peak were 570ºC and 7 kb at the basement-cover interface. These results can be reconciled both with models in which tectonic burial alone was sufficient to cause Alpine metamorphism of the Pennine Zone and with models in which a transient high heat flow regime is invoked.
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The structure and metamorphic evolution of the High Himalayan Slab in SE Zanskar and NW LahaulWalker, James David January 1998 (has links)
This thesis attempts to unravel the complex thermal and structural history of part of the High Himalayan Slab in NW India and combines reconnaissance-style field structural mapping of an area covering ~10,000 km<sup>2</sup> with petrography, microstructural analysis, thermobarometry and geochronology techniques. The results of this work show that the oldest protoliths of the High Himalayan Slab are at least Cambrian in age and that they may have experienced a major pre-Himalayan metamorphism at c.500 Ma. The youngest protoliths are Mesozoic in age (the Tandi Group) and demonstrate that the High Himalayan Slab represents the metamorphosed equivalents of the Tibetan Sedimentary Series. Metamorphism was achieved via substantial crustal shortening and thickening following the India-Asia collision at 50-54 Ma ago. Phase relationships demonstrate that metamorphism was a regional Barrovian-type event associated with the growth of biotite-, garnet-, staurolite-, kyanite- and sillimanite-bearing assemblages in metapelites. Quantitative thermobarometry demonstrates that near-peak conditions of c.6-8 kbar and 550-650°C were attained in the deepest exposed levels. Growth of metamorphic assemblages was underway by at least 30 Ma, as indicated by U-Pb ages of metamorphic monazites. Exhumation of the High Himalayan Slab was achieved through a combination of extensional unroofing along major detachments (namely the Zanskar Shear Zone), thermal doming, thrusting along the Main Central Thrust and surface erosion. Exhumation is closely associated with the growth of sillimanite- and cordierite-bearing assemblages in pelites and the generation and emplacement of crustal melt leucogranites in the upper parts of the slab. U-Pb dating of accessory phases from one of the crustal melt leucogranites (the Gumburanjon leucogranite) constrains its crystallisation and emplacement age at c.21-22 Ma. This is only slightly older than its <sup>40</sup>Ar/<sup>39</sup>Ar muscovite and biotite cooling ages of c.20-21 Ma, which is attributed to the emplacement of the Gumburanjon leucogranite into the immediate footwall of the ZSZ. Field and geochronological data therefore support a strong temporal and spatial relationship between upper crustal melting and extension in a convergent orogen.
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Structural geology and geochronology of the Kluane schist, southwestern Yukon TerritoryStanley, Benjamin January 2012 (has links)
In light of the recent increase of mineral exploration in the northern Cordillera, private, educational, and governmental agencies have been compelled to revisit and research areas of the Cordillera whose geologic evolution still remains enigmatic. The current study is concerned with better understanding how a region of the boundary zone separating the peri-Laurentian realm from the exotic, Insular realm evolved following deposition of the meta-sedimentary Kluane schist in the Late Cretaceous. The schist is a northwest striking 30 km wide and 160 km long belt of highly deformed greenschist to amphibolite facies meta-sedimentary rocks located east of Kluane Lake, southwestern Yukon Territory. These deformed sediments as well as numerous other deformed Jurassic-Cretaceous meta-sedimentary units present along the same boundary zone (north and south of the schist) represent important rocks that can help constrain how this part of the Cordillera has evolved since the mid-Mesozoic.
To better understand how the Kluane schist evolved, detailed field mapping, petrography, and U-Pb geochronological studies were undertaken in the area encompassing the schist. This data is integrated with pre-existing and recently collected geologic databases from the region to propose a model for the tectonic and structural evolution of the Kluane schist. Conclusions drawn from this study indicate the Kluane sediments were likely deposited into a closing Late Cretaceous seaway from sources derived from Yukon-Tanana terrane (YTT) to the east. The basin into which the sediments were deposited represents a remnant ocean basin that was present between Insular terrane and YTT prior their amalgamation in the Jurassic. Thrusting of YTT over the Kluane schist basin resulted in burial, metamorphism, and ductile deformation of the schist. Contemporaneously, the early stages of the Ruby Range batholith (RRB) were intruding the schist as well as the schist/YTT contact. This batholith intruded syn- to post-tectonically from approximately ca. 77 Ma to 65 Ma and it is responsible for imparting a kilometer scale inverted contact metamophic aureole onto the Kluane schist wherein metamorphic grade decreases to the southwest. Subsequently, a gneissic sub-unit of the Kluane ‘schist’ was formed by partial melting of the RRB/Kluane schist contact. During this composite deformation event, the schist was transported to mid-crustal depths by an oblique sinistral shear zone. Shortly thereafter, the schist was exhumed and deformed by consistent northeast-over-southwest shearing. Regional scale, broad open folding of the schist ensued and likely occurred by flexural slip along foliation planes with low cohesion. Two syn- to post- tectonic igneous phases associated with Hayden Lake intrusive suite have been dated to ca. 55 Ma. This timing likely correlates with broad, open folding and a ‘late’ syn- to post-kinematic thermal overprint of the schist. The combined results of this study indicate that deformation and metamorphism of the Kluane schist was a long-lived event, extending from ca. 82 Ma to ca. 55 Ma.
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Metamorphism and folding in the Mt. Lofty Ranges, South Australia, with particular reference to the Dawesley-Kanmantoo areaFleming, Peter David January 1971 (has links)
2 v. : ill. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology and Minerology, 1972
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