نتایج جستجو برای: plagioclase
تعداد نتایج: 1579 فیلتر نتایج به سال:
Major and trace element composition of silicate melt inclusions (SMI) their rock-forming minerals were studied in mafic garnet granulite xenoliths from the Bakony–Balaton Highland Volcanic Field (Western-Hungary). Primary SMIs occur clinopyroxene plagioclase plagioclase-rich domains granulites ilmenite vicinity these wall rock. Based on major elements, we demonstrated that have no connection wi...
Introduction: Water liquid has been considered to be main fluid in cold Mars, though major sources of liquid water are not clearly found on Martian surfaces. Recently author (Y.M.) found carbon-bearing grains on plagioclase composition in druses of terrestrial volcanic basalts in Shimonoseki, Yamaguchi, Japan [1], where many scientists have been reported as normal “plagioclases” formed at hydro...
Fine scale heterogeneities in strontium isotope ratios, 40Ar-39Ar ages, and chemical com~sition have been determined for individual mineral grains and enclaves in the rhyolites of San Vincenzo, Italy. The rhyolites are peraluminous with phenocrysts of alkali feldspar, piagioclase, biotite, and cordierite and have previously been divided into two groups on the basis of whole rock major element c...
Spinel + plagioclase symplectites in pelitic metamorphic rocks have been reported from many localities. We report detail an occurrence of this texture Tenmondai Rock, Lützow-Holm Complex, East Antarctica. This is produced by the following reaction; garnet sillimanite = spinel plagioclase. can be described as two net-transfer reactions; 5Grs Alm 12Als 3Hc 15An, and Prp 3Spl 15An. propose new geo...
Previous studies have shown that the 2.04 Ga Kangâmiut dyke swarm of SW Greenland was injected into an active tectonic environment associated with the formation of the Nagssugtoqidian orogenic belt. Major and trace element modelling of the swarm shows that its chemical evolution was controlled by simple clinopyroxene–plagioclase fractionation. However, such trends — although typical of continen...
Five calc-alkaline plutons; Um Tagher, Abu Zawil, Um Gidri, Um Anab and El Ghuzah, in the northern Eastern Desert of Egypt were subjected to petrographic and mineralogical investigations. They are composed of varying proportions of quartz + plagioclase +potash feldspar+ biotite + hornblende± epidote ± calcite + titanite +magnetite + apatite and zircon. Electron microprobe analyses of coexisting...
The eclogite facies assemblage K-feldspar–jadeite–quartz in metagranites and metapelites from the SesiaLanzo Zone (Western Alps, Italy) records the equilibration pressure by dilution of the reaction jadeite+quartz=albite. The metapelites show partial transformation from a pre-Alpine assemblage of garnet (Alm63Prp26Grs10)–K-feldspar–plagioclase–biotite±sillimanite to the Eo-Alpine high-pressure ...
Introduction: Volcanism is the primary process in the solar system that creates the surfaces of the terrestrial planetary bodies. Volcanoes and volcanic surface units provide information about the geologic history of these bodies, which reflects the unique thermal and chemical evolution of each. Remote sensing provides an effective means to study these volcanic surface units in a quantitative w...
Abstract Chang’e-4 landed in the Von Kármán basaltic zone affected by Finsen ejecta from South Pole-Aitken (SPA) “compositional anomaly” (SPACA), providing an opportunity to untangle origin of SPACA. We developed a mineral abundance unmixing model and built spectral library composed mixtures plagioclase, low-Ca pyroxene, high-Ca olivine. Based on abundances returned our model, average plagiocla...
Plagioclase-bearing rocks were first detected in the vicinity of large impact basins on Mars using visible/near-infrared (VNIR) data. The geologic context is consistent with excavated plutons or ancient crustal outcrops. Our analyses reveal plagioclase outcrops exposed a 200 m thick, sub-horizontal layer 8 km deep walls Valles Marineris canyon. These plagioclase-bearing are either sill, volcano...
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