نتایج جستجو برای: mafic composition
تعداد نتایج: 261231 فیلتر نتایج به سال:
Karapınar-Karacadağ Volcanic Rocks (KKVR) have very complex magmatic history and outcropped the southwestern part of Cappadocia Province (Central Anatolia). Here we present petrography whole-rock chemistry enclave-bearing rocks to constrain their source evolution history. These petrographic observation geochemical data reveal that enclaves in volcanic are magma mixing/mingling (MME), segregatio...
Introduction: The secondary mineralogy of martian surface materials is consistent with aqueous alteration of mafic and ultramafic rocks [e.g., 1-3]. Alteration of mafic silicates results in the release of SiO2 into aqueous solution, followed by the precipitation of silica [4] and/or silica-rich minerals. The presence of these phases is consistent with data obtained at the Mars Pathfinder [4] an...
Zircon grains were separated from lunar regolith and rocks returned from four Apollo landing sites, and analyzed in situ by secondary ion mass spectrometry. Many regolith zircons preserve magmatic dO and trace element compositions and, although out of petrologic context, represent a relatively unexplored resource for study of the Moon and possibly other bodies in the solar system. The combinati...
Composition of the Kiyamaki dome has mostly dacite and granodiorite in rims, with SiO2 contents ranging from 64 to 73 wt% and Mg# values ranging from 27 to 57. These rocks are high-Si adakite. Geochemical characteristics and Sr and Nd isotopic rates indicate that the rocks of Kiyamaki dome are a post-collisional adakite. Combined geochemical and Sr–Nd isotope data suggest that the Kiyamaki adak...
Both Sangan and Tannurjeh magnetite deposits are Iron-oxides type. Geochemistry and petrography of source rocks at Tannurjeh and Sangan were studied in detail. The source rocks at Sangan are compused of quartz hornblende alkali syenite porphyry and quartz biotite-hornblende alkali syenite porphyry ; while The source rocks at Tannurjeh varies between hornblende quartz diorite porphyry and h...
Abstract The exposed rocks in Abu Hawis area, North Eastern Desert (NED), Egypt, consist of tonalite-granodiorite and monzogranite, dissected by post-granite felsic (microgranite rhyolite) mafic (basaltic-andesite) dikes. investigated radioactive minerals Zr-, Nb-, REE-bearing were restricted to dikes having E–W NE–SW trends. Uraninite, uranothorite, thorite occur as the main microgranite dikes...
Exposures of enclave-bearing granitoids can provide rare opportunities to directly evaluate the connection between compositional variability and depth origin arc magmatic rocks. The ∼1000 km long Gangdese batholith is a composite with composition from mafic felsic; SiO2 ranges 51 wt% 70 wt%. New zircon U−Pb dating Nyemo plutons, Renbu Xigaze plutons in consistent their emplacement crystallizati...
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