نتایج جستجو برای: ultramafic rocks
تعداد نتایج: 22653 فیلتر نتایج به سال:
ONE petrological approach to upper mant le studies is to determine which ultramafic rocks represent mantle material. Ultramafic rocks occur in a variety of field and petrographic associations : in recent reviews, Wyllie [1967b, 1968] outlined eleven petrographic associations, some with subdivisions. In this summary, it is convenient to consider these in four larger groups: (1) layered, stratifo...
A gravity and geologic survey was carried out over a port ion of the Nelson ultramafic belt of the South Island . In this region, the ultramafic rocks outcrop over a 5-mile-wide belt and abut against the Alpine greywacke along the right lateral transcurrent Alpine Fault. The dunite and peridotite of the ultram afic belt as well as the overlying geosynclinal sediments strike north . At their sou...
mafic and ultramafic plutonic igneous bodies, with small and big outcrops, between shemshak rock units (jurassic) are observed in east of imam zadeh hashem, in southern guilan province. ultramafic cumulates consist of clinopyroxenite, and plagiofer clinopyroxenite, olivine clinopyroxenite, and mafic rocks, based on mineralogy consist of gabbros, olivine gabbros, biotite gabbros and amphibole ga...
1 Geological carbon capture and storage in mafic and ultramafic rocks – Muscat, 2011
Archean Quartzose Rocks at Akilia, Greenland Fedo and Whitehouse (1) presented data to support their hypothesis that granulite grade quartz magnetite rocks on the island of Akilia, southwest Greenland—which are conformably interposed with pyroxenite and hornblendite units that date from before 3830 million years ago (Ma) (2–4)—had a metasomatic ultramafic igneous origin. They offered that inter...
Archean Quartzose Rocks at Akilia, Greenland Fedo and Whitehouse (1) presented data to support their hypothesis that granulite grade quartz magnetite rocks on the island of Akilia, southwest Greenland—which are conformably interposed with pyroxenite and hornblendite units that date from before 3830 million years ago (Ma) (2–4)—had a metasomatic ultramafic igneous origin. They offered that inter...
Osmium isotope compositions and concentrations of Re, platinum group elements (PGE), and Au were determined for host peridotites (serpentinites and harzburgites) and hydrothermally altered ultramafic wall rocks associated with Mother Lode-type hydrothermal gold-quartz vein mineralization in the Alleghany district, California. The host peridotites have Os isotope compositions and Re, PGE, and Au...
anomolously low A1203, low Ti02 and are enriched in chromium and nick~A We present petrographic and chemical c ata on the Kamloops Lake picritic tmalts as we1 I as the stratigraphic setting for thwe ultramafic lavas. Age constraints derive From field relationships, Mineral chemistry indicates th 31 these ultramafic rocks represent mantle-deri.ed material which has undergone: minimal differentia...
Three distinct groups of eclogites (low-Mg–Ti eclogites, high-Ti eclogites and Mg-rich eclogites) and ultramafic rocks from the depth interval of 100–680 m of the Chinese Continental Scientific Drill Hole were studied. The lowMg#s (=100⁎molar Mg/(Mg+Fe)) (81–84%) and low Ni (1150–1220 ppm) and high Fe2O3 total (13–15 wt.%) contents of ultramafic rocks suggest a cumulate origin. Mgrich eclogites...
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