نتایج جستجو برای: podiform chromite deposits
تعداد نتایج: 29153 فیلتر نتایج به سال:
“Laoshan Jade” is located in the Yangkou area of Sulu UHP metamorphic belt. This first time a systematic research study performed on its conventional gemological characteristics, mineral compositions, geochemical and petrogenesis using polarized light microscope, an electron probe microanalyzer (EMPA), X-ray fluorescence spectrometer (XRF), Raman spectrometer. The characteristics are consistent...
The hand stencils of European Paleolithic art tend to be considered of pre-Magdalenian age and scholars have generally assigned them to the Gravettian period. At El Castillo Cave, application of U-series dating to calcite accretions has established a minimum age of 37,290 years for underlying red hand stencils, implying execution in the earlier part of the Aurignacian if not beforehand. Togethe...
The paper provides results of a detailed mineralogical study some chromitite ores from two deposits in the Southern Urals Kazakhstan: Almaz-Zhemchuzhina and Geofizicheskoe-VII. It is revealed that main ore minerals are Cr-spinel with high Cr# (Cr/(Cr + Al) = 0.8–0.83), as well serpentine chlorite, replacing primary olivine. Chromium spinel grains contain mineral inclusions, which distributed ra...
IN CHROMITE VERSUS SEDIMENTARY PGE SIGNATURES B. Schmitz , P. R. Heck, C. Alwmark, N. T. Kita, B. Peucker-Ehrenbrink, T. Ushikubo, and J. W. Valley, Department of Geology, Sölvegatan 12, Lund University, SE-22362 Lund, Sweden, [email protected], Department of Geology and Geophysics, University of Wisconsin, 1215 W. Dayton St., Madison, WI 53706, USA, Department of Marine Chemistry and G...
Hydrocarbons such as CH4 are known to be formed through the Fischer-Tropsch or Sabatier type reactions in hydrothermal systems usually at temperatures above 100°C. Weathering of olivine is sometimes suggested to account for abiotic formation of CH4 through its redox lowering and water splitting properties. Knowledge about the CH4 and H2 formation processes at low temperatures is important for t...
Side scan sonar in low-cost 'fishfinder' systems has become popular in aquatic ecology and sedimentology for imaging submerged riverbed sediment at coverages and resolutions sufficient to relate bed texture to grain-size. Traditional methods to map bed texture (i.e. physical samples) are relatively high-cost and low spatial coverage compared to sonar, which can continuously image several kilome...
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