نتایج جستجو برای: mafic migmatites

تعداد نتایج: 2136  

2009
B. L. Jolliff R. L. Korotev R. A. Zeigler T. H. Prettyman

Introduction: Lunar meteorite Dhofar 961, a complex, lithic-clast-rich impact breccia [1,2], was called out by [3-6] as a candidate for an origin in the South Pole – Aitken (SPA) Basin region of the Moon (the SPA Terrane) on the basis of its relatively mafic, but nonmare lithologic and major-element chemical composition. It also has an incompatible-element signature that differs from the KREEP-...

2004
S. P. Turner C. J. Hawkesworth

Large Ra excesses in a number of mafic arc magmas, and geophysical observations of earthquake hypocenters locations, indicate that mafic melts can get transferred from source to surface within days to ~1 kyr. Decreasing Ra–Th disequilibria with increasing SiO2 in co-magmatic suites of individual arc volcanoes suggest that magma differentiation often occurs on timescales of a few thousand years ...

1997
Jongman Lee Robert J. Stern

Major element compositions of glass inclusions in olivine and plagioclase phenocrysts from representative Mariana arc lavas show that mafic Mariana arc liquids are tholeiitic and not high-alumina, implying that the high-alumina characteristic of these lavas reflects accumulation of plagioclase. Glass inclusions also show the common occurrence of felsic melts previously unrecognized among Marian...

Journal: :E3S web of conferences 2021

The mineral exploration has improved in the last decades, today there are different methods of remote exploration, that applied mining industry worldwide, helping to discover ore minerals deposits zones have not access them. study area this article is located about 400 km from Khartoum, characterized by low reliefs covered sand and gravely sand. wants carry out geological mapping prospective us...

Journal: :Geoscience frontiers 2022

• Continental crust was formed during metamorphic events in amalgamated supercontinents. Granites by dehydration melting (upper crust) and mantle-derived fluids (lower crust). Mantle reach the middle-upper along shear zones generate granites. Until middle of 20th century, continental considered to be dominantly granitic. This hypothesis revised after Second World War when several new studies le...

Journal: :Journal of the Virtual Explorer 2011

2007
Lisa R. Gaddis B. Ray

Clementine ultraviolet-visible (UVVIS) data are used to examine the compositions of 18 pyroclastic deposits (15 small, three large) at 13 sites on the Moon. Compositional variations among pyroclastic deposits largely result from differing amounts of new basaltic (or juvenile) matehal and reworked local matehal entrained in their ejecta upon eruption. Characterization of pyroclastic deposit comp...

2009
Gaud Pouliquen Roger Key Adrian Walker

The Xade Complex is an unexposed Y-shaped body, approximately 100 km long and 25km wide, located close to the western margin of the Kaapvaal craton in Botswana. The Complex is characterized by large coincident magnetic and gravity anomalies. It is completely covered by varying thicknesses of Kalahari sediments as well as by Karoo strata, which means that detailed analysis of high resolution air...

2015
Shohei Kaneko Masaaki Miyahara Eiji Ohtani Tomoko Arai Naohisa Hirao Kazuhisa Sato

High-pressure polymorphs recovered in terrestrial craters are evidence of meteoroid impact events on the Earth’s surface. Despite countless impact craters on the Moon, high-pressure polymorphs have not been reported to date in returned Apollo samples. On the other hand, recent studies report that the high-pressure polymorphs of silica, coesite and stishovite occur in shocked lunar meteorites. W...

2008
A. H. Nasr T. M. Ramadan Joseph Broz

The main objective of the remotely sensed data fusion is to create an integrated composite image of improved information and enhanced interpretability. This data have geospatial details about earth’s surface for substantial assessment of land resources and mineral exploration. Fusion of Visible-Infrared (VIR) and Synthetic Aperture Radar (SAR) images provides complementary data to increase the ...

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