Possible sub-arc origin of podiform chromitites
نویسندگان
چکیده
منابع مشابه
Platinum-group Minerals in Podiform Chromitites of the Oman Ophiolite
Chromitite lenses rich in the platinum-group elements (PGE) have recently been discovered in the deeper part of the mantle section of the northern part of the Oman ophiolite. In terms of stratigraphic level, there are two types of chromitite: Moho transition zone (MTZ) and mantle types. The mantle type can be further classified into two subtypes: PGE-poor and PGE-rich. Platinum-group minerals (...
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The ultramafic portions of the Proterozoic ophiolite, Eastern Desert, Egypt, contain significant chromitite concentrations that are mainly located in the central and southern parts of the Eastern Desert as small and irregular bodies within a fully serpentinized dunite and harzburgite. Chromitite spinel exhibits a wide range of composition from high Cr to high Al varieties. The Cr# of chromian s...
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The podiform chromitite deposits of the Ordovician Sorkhband ultramafic complex, southwestern Makran, are the largest chromitite deposits in Iran. The Sorkhband ultramafic complex comprises of a northern part of dunite, podiform chromitite, olivine clinopyroxenite, wehrlite and olivine websterite and a southern part of foliated diopsidic harzburgite with subordinate dunite, olivine clinopyroxen...
متن کاملOrigin of Kern's arc.
With the aid of computer-simulated halo patterns, we show that Kern's arc, as seen on the latitude of the circumzenithal arc and on the other side of the zenith, is produced by double-plate ice crystals with a vertical principal axis. Light rays that contribute to Kern's arc are demonstrated by geometric ray tracing. We also discuss the condition under which an arc that is opposite a circumhori...
متن کاملOrigin of the Parry arc
Laboratory experiments to determine the preferred orientation of free-falling hexagonal prisms were performed at Reynolds numbers appropriate to falling ice crystals in the atmosphere. Hexagonal plates orient with their c axis vertical for aspect ratios < 0.9, whilst hexagonal columns fall with their c axis horizontal. A secondary alignment is also observed: regular hexagonal columns fall prefe...
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ژورنال
عنوان ژورنال: The Island Arc
سال: 1995
ISSN: 1038-4871,1440-1738
DOI: 10.1111/j.1440-1738.1995.tb00135.x