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Showing 1 to 13 of 13 for “"Geothermobarometry"”.
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Geochemistry, Geothermobarometry and Geochronology of High-Pressure Granulites and Implications for the Exhumation History of Ultrahigh-Pressure Terranes: Dulan, Western China
<p>The Dulan ultrahigh-pressure (UHP) rocks of the North Qaidam terrane, Western China, represent continental crust that has been subducted ~100 km during continental collision. Adjacent granulites representing burial to ~50 km could either be overprinted eclogites or a separate …
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Petrogenesis and geochemistry of kyanite-bearing pegmatites in the Buncombe Pegmatite District, North Carolina
… kyanite and sillimanite as primary phases, and geothermobarometry on nearby unaltered rocks all indicate conditions of formation of approximately 600-800 MPa and 625-675°C, near those of peak metamorphism for the region.
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Structural and petrologic aspects of the emplacement of granitoid plutons : case studies from the western margin of the Joshua Flat-Beer Creek-Pluton (White-Inyo Mountains, California) and the Flasergranitoid zone (Odenwald, Germany)
… granitic plutons were determined with hornblende geothermobarometry. The plutons intruded into a depth of 13 to 20 km at temperatures between 600 and 800°C. Most of the igneous rocks from the Flasergranitoid Zone (Germany) show a pronounced planar fabric. Structural investigations of the …
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A study of mantle inclusions in the Koffiefontein Kimberlite Pipe, South Africa
… by the diamond inclusions. Attempts to apply geothermobarometry to the pyroxenites and to the diamond inclusions gave conflicting results which are ascribed to lack of equilibration between co-existing mineral phases and/or within individual mineral grains. The Koffiefontein xenolith suite is …
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The record of magma storage conditions in mineral compositions below a glacial to ice-free Askja volcano, Iceland
… could involve melt inclusion analysis and geothermobarometry to constrain specific depths and pressures at which the crystals in the lavas formed. By investigating mineral compositions and textures and analyzing the implications on crystal cargo and magma storage throughout a period of …
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Monogenetic volcanism in the western Arabian Peninsula: Insights from Late Quaternary eruptions in northern Harrat Rahat, Kingdom of Saudi Arabia
… as plume-like. Trace element modelling and geothermobarometry reveal that partial melting occurred in the asthenospheric mantle (>100 km depth, ~1500 °C, >3 GPa). Fractionation of olivine and clinopyroxene en route to the surface can account for variations in composition. The elevated …
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THE INTERPLAY BETWEEN CATION ORDERING AND ELASTICITY OF OMPHACITES TO UNRAVEL PTT PATHS OF METAMORPHIC ROCKS
… makes it a valuable candidate for Raman elastic geothermobarometry, a method that uses the deformation recorded by mineral inclusions to determine the pressure and temperature conditions under which they were entrapped. Raman scattering, which is highly sensitive to structural deformations, …
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Metamorphic evolution of ultrahigh-temperature granulite facies and upper amphibolite facies rocks of the Epupa Complex, NW Namibia
… UHT-Metamorphism is proved by conventional geothermobarometry (970 +/- 70°C; 9.5 +/- 2.5 kbar), by the very high Al content of peak-metamorphic orthopyroxene (up to 11.9 wt.% Al2O3) in many paragneisses and by Opx-Sil-Qtz assemblages in the MgAl-rich gneisses. Post-peak decompression is …
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Petrogenesis of the Mesoproterozoic anorthosite, syenite and carbonatite suites of NW Namibia and their contribution to the metasomatic formation of the Swartbooisdrif sodalite deposits
… into albite and sodalite. Applying conventional geothermobarometry combined with fluid-inclusion isochore data, it was possible to reconstruct the P-T conditions for the carbonatite emplacement and crystallization (1200-630°C, 4-5 kbar) and for several mineral-forming processes during …
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Quantifying crystalline exhumation in the Himalaya
… of key minerals, microprobe analyses, standard geothermobarometry and modelling using an effective bulk rock composition it has been shown that published exhumation paths are incomplete. In particular, the eclogites of the northern Kaghan Valley were buried to depths of 140-100 km (36-30 kbar) …
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Gold mineralization in the Um El Tuyor area, South Eastern Desert, Egypt
… conditions of amphibolite facies during D2. Geothermobarometry calculations point to temperatures of 534-561oC and pressure of 5.26-6.20 kbar for the peak of the metamorphic path of Um El Tuyor basement. Gold is mainly confined to the quartz veins and less commonly to narrow domains of the …
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Metamorphoseentwicklung im Kaokogürtel, NW-Namibia
Der Kaokogürtel in NW-Namibia gehört zu den panafrikanischen Orogensystemen Westgondwanas. Er besteht aus präpanafrikanischen Grundgebirgseinheiten und panafrikanischen vulkano-sedimentären Deckgebirgseinheiten, die einer grünschiefer- bis granulitfaziellen Metamorphose unterlagen. Für Metapelite …
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Timescales of magma residence and transport underneath Iceland
The focus of this thesis is the development and application of a new method of diffusion chronometry known as DFENS (Diffusion chronometry using Finite Elements and Nested Sampling). This method combines a flexible finite element numerical model with a nested sampling Bayesian inversion to provide …