نتایج جستجو برای: chromitite
تعداد نتایج: 108 فیلتر نتایج به سال:
Abstract New trace-element, radiogenic Sr-Nd-Pb isotopic and geochronological data from Middle-Late Cretaceous Zagros ophiolites of Iran give new insights into the tectono-magmatic history these supra-subduction zone (SSZ)-type ophiolites. The distribution SSZ-type in comprises two parallel belts: (1) outer ophiolitic belt (2) inner belt. These were generated by seafloor spreading what became f...
baft ophiolite mélange is a part of naein-baft ophiolite (southeast of kerman province in iran). serpentinites from baft ophiolite mélange contain different types of spinels such as chromite, chromespinel, ferritchromite and magnetite which can reveal different stages of evolution in host serpentinites. the compositions of baft chromites show that they belong to podiform chromitites that may ha...
Abstract Discordant iron-rich ultramafic pegmatites (IRUPs) intersect the UG2 chromitite at many places in Bushveld Complex. The effects of IRUP interactions on ore mineralogy and PGE grade are assessed Thaba mine, north-west Bushveld, based a borehole profile through layer detailed analysis mineral textures compositional variations across UG2-IRUP contacts using micro-XRF element mapping. inte...
The about 2055-Ma-old mafic to ultramafic Uitkomst Complex in the Mpumalanga Province of South Africa hosts low-grade-large-tonnage Ni-Cu-PGE deposit, Nkomati. complex is regarded represent a satellite Bushveld and feeder an eroded magmatic reservoir southeast. Aeromagnetic surveys previous drilling indicated overall northwestern-downdip extension complex, but question what extent which express...
Mantle peridotites exposed in south Jazmourian comprise of lherzolite and porphyroclastic Cpx-bearing harzburgite in the lower part with chromitite lenses in the upper parts. Petrography and microprobe studies shows evidence of melt-peridotite interactions; post melting processes and subsolidus interactions, which has been associated with appearance of two generations of deformed primary pyroxe...
Gushk chromite mine is one of the largest and the most important chromite mines in Iran that is located in southwest of Kerman Province, 5 km north of Baft city. In this open pit active mine, about 60 tons of chromite is extracted per day. The studied chromitites are podiform type and form discontinuous layers or lenses surrounded by completely serpentinized dunites. The chromites with average ...
Mantle peridotites are one of the most important rock units of Jandaq ophiolite that are affected by numerous,phases of dynamic and static serpentinization, and metamorphism. The main part of mantle peridotites is lherzolite. This ophiolitic association is covered by Paleozoic metamorphic rocks that are schist and marble. All olivines are changed to serpentine. Most of orthopyroxenes are b...
The chromitite ores of Sabzevar ophiolitic zone could be divided into two groups of high Cr and high Al. The concentration of Cr2O3, As, S and some heavy metals (Cu, Ni, Ag, Co, Zn) is higher in high Cr samples; while high Al chromitites show higher concentration of Al2O3, SiO2, TiO2 and other trace elements. The high Cr chromitites have higher PGE than Al-rich samples and PGE concentration inc...
Niabad-Qalaje ophiolitic complex is part of Sarvabad ophiolites in Kurdistan that exposed in northwest of Iran and the north of Kermanshah Ophiolites. The complex located in north of Zagros orogeny, consists of lens form, tectonically dismembered ophiolitic sequences located along the main Zagros trust. The ultramafic part includes serpentinized dunite and wherlite, serpentinite and chromitite ...
Abstract The mantle–crust boundary beneath oceanic spreading centres is a major chemical and thermal interface on Earth. Observations in ophiolites reveal that it underlined by dunitic transition zone (DTZ) can reach few hundred meters thickness host abundant chromitite ore bodies. dunites have been deciphered as essentially mantle-derived most ophiolitic massifs; is, reactional residues of int...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید