نتایج جستجو برای: alkali olivine basalt
تعداد نتایج: 22347 فیلتر نتایج به سال:
Crustal assimilation (e.g. Hildreth and Moorbath, 1988) and/or subduction erosion (e.g. Stern, 1991; Kay et al., 2005) are believed to control the geochemical variations along the northern portion of the Chilean Southern Volcanic Zone. In order to evaluate these hypotheses, we present a comprehensive geochemical data set (major and trace elements and O–Sr–Nd–Hf–Pb isotopes) from Holocene primar...
The study area is located in northwest of Birjand, northern part of the Sistan suture zone in eastern Iran. There is well preserved outcrops of an ophiolite mélange in this area. This complex is composed of harzburgite, layered gabbro and spilitic basalt with flysch type rocks. Microprobe analyses of olivine, clinopyroxene, orthopyroxene and spinel in harzburgites show that olivine is forsterit...
Petrologic analysis of the lunar surface is critical for determining lunar formation and evolution. Here, we report the first global petrologic map that includes the five most important lunar lithological units: the Ferroan Anorthositic (FAN) Unit, the Magnesian Suite (MS) Unit, the Alkali Suite (AS) Unit, the KREEP Basalt (KB) Unit and the Mare Basalt (MB) Unit. Based on the petrologic map and...
The Cenozoic volcanic activity of the Harrat Ash Sham volcanic field in south of Syria is a part of the extensive magmatism that took place in the auxiliary extension faults along the Dead Sea Fault Zone from upper Eocene to Holocene. Pliocene volcanic rocks form an important part of igneous succession in Syrian Part of Harrat as Sham. These rocks vary from basalts flows to scoria. Pliocene bas...
there are three different basic dykes in the northeast of golpayegan area, central part of sanandaj-sirjan zone (ssz) including: mylonitic gabbros (group 1), alkali dioritic-basanitic dykes (group 2) and alkali monzogabbroic to monzodioritic dykes (group 3). group 2 and 3 cut post-collisional rocks and are related to after subduction processes of neo-tethys. geochemistry characteristic of studi...
Northwest Africa (NWA) 11962 is a lunar regolith breccia composed of wide range different clasts. The origin this meteorite confirmed by oxygen isotope analysis and the Fe/Mn ratio in pyroxene olivine. In present study, clasts matrix NWA are characterized optical electron microscopy along with microprobe analyses micro-Raman spectroscopy. has glassy impact melt matrix, which accounts for 35% su...
Near-surface reaction of CO2-bearing fluids with silicate minerals in peridotite and basalt forms solid carbonate minerals. Such processes form abundant veins and travertinedeposits, particularly in associationwith tectonically exposed mantle peridotite. This is important in the global carbon cycle, in weathering, and in understanding physical-chemical interaction during retrograde metamorphism...
Studies of the origin of magmas in subduction zones, particularly in the Japanese island arc, have been significantly advanced by petrological, geochemical, geophysical and experimental studies during last 50 years. Kuno's original model(1)) for magma generation in the Japanese island arc, that tholeiite magmas are formed at relatively shallow levels in the mantle on the Pacific Ocean side wher...
Olivine and Carbonate Globules in Alh84001: a Terrestrial Analog, and Implications for Water on Mars
Carbonate globules in ALH84001 are associated with small olivine grains [1] – an unexpected finding because the olivines equilibrated at high T while the carbonate is chemically zoned and unequilibrated. A possible explanation comes from a terrestrial analog on Spitsbergen (Norway) [2], where some carbonate globules grew in cavities left by aqueous dissolution of olivine. For ALH84001, the same...
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