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Widespread arc-related melting in the mantle section of the northern Oman ophiolite as inferred from detrital chromian spinels
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Abstract:
We examined detrital chromian spinels, in recent river beds, derived from the mantle section to determine whether the mantle peridotite of the northern Oman ophiolite is of oceanic or arc origin. The Cr-number (= Cr/(Cr + Al) atomic ratio) of the detrital chromian spinels mostly ranges from 0.4 to 0.8, and more than 60% of them have Cr-numbers higher than 0.6. This indicates a significant extent of island-arc nature because chromian spinels seldom have Cr-numbers higher than ...
Related newspaper, magazine, and journal articles from HighBeam Research
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Melt extraction from the mantle beneath mid-ocean ridges.
Oceanus
; As the oceanic plates move apart at mid-ocean ridges, rocks from Earth's mantle, far below, rise to fill the void, mostly via slow plastic flow. As the rock approaches the top of its journey, however, partial melting occurs, so that the upper 6 kilometers of oceanic crust are composed of melts,
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Structure and petrology of the Altan Uul Ophiolite: new evidence for a Late Carboniferous suture in the Gobi Altai, southern Mongolia
Journal of the Geological Society
; ... constrained by biostratigraphy derived from shallow-marine argillaceous sedimentary rocks (Badarch et al. 2002) and Russian-Mongolian maps (Anonymous 1990). During fieldwork in 2004 and 2005, a suite of mafic and ultramafic rocks was studied in western Alla
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Discussion on subsidence history of the north Indian continental margin, Zanskar-Ladakh Himalaya, NW India
Journal of the Geological Society
; E. Garzanti, D. Sciunnach & M. Gaetani write: In their recent paper, Corfield et al. (2005) attempted a subsidence analysis of the northwestern Tethys Himalaya stratigraphie succession, and discussed specifically the implications for the obduction of a section of oceanic lithosphere (Spontang
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Mn^sup 3+^-rich andalusite to kanonaite and their breakdown products from metamanganolite at Kojetice near Trebíc, the Moldanubian Zone, Czech Republic
Journal of the Czech Geological Society
; A zoned Mn^sup 3rich andalusite to kanonaite occurs as shortly prismatic, black-green crystals, up to 2 mm in size, randomly distributed in quartz matrix of quartzitic rock with metamanganolite portions from Kojetice near Trebic. Minor spessartine, braunite, K-feldspar, albite, hyalophane, rare
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Unraveling the tapestry of ocean crust: scientists follow a trail of clues to reveal the magmatic trickles and bursts that create the seafloor.(Creating the Seafloor)
Oceanus
; Most people know that oceans cover about 70 percent of Earth's surface. Fewer people realize that the crust beneath oceans and continents is fundamentally different. Why this is so remains a mystery that scientists are still trying to solve. Oceanic crust is generally composed of dark-colored rocks
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The minerals industry of Oman. (Industry Overview)
Mining Magazine
; ... previously unknown copper deposits. It is now possible to produce 1:1,000,000-scale geological maps, as well as 1:50,000-scale magnetic and radiometric maps, to assist in mineral exploration and underground water resources. Oman possesses the world ...
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Formation and emplacement of the Northland ophiolite, northern New Zealand: SW Pacific tectonic implications
Journal of the Geological Society
; Abstract: Petrological, geochemical, geochronological and palaeomagnetic data for rocks of the Northland ophiolite terrane of northern New Zealand suggest that it formed in a suprasubduction-zone setting between c. 29 and 26 Ma. at c. 35S. close to its Late Oligocene obduction site. Cretaceous
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The India-Asia collision: what gives? (possible flaw in theory of plate tectonics; collision causes damage thousands of kilometers from edges of plates) (Brief Article)
Science News
; The Tibetan plateau rises above the rest of the planet's surface like a giant welt. And for scientists, this part of Asia is truly a bit of a sore spot. The plateau and mountains to the north reveal an apparent flaw in the elegant theory of plate tectonics, which holds that Earth's thin outer
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