The chemical composition of obsidian samples from 28 sources in Western America is that of a high alumina glass (ca. 12 wt% Al 2O 3) with a silica content exceeding that of normal granite. Considerable complexity of phase states is indicated by a wide range of variability of properties. ...
select article Carbonate-associated sulfate as an archive of sulfur and oxygen stable isotope composition of seawater sulfate: Evidence from reef carbonate rocks of the southern South China Sea Research articleAbstract only Carbonate-associated sulfate as an archive of sulfur and oxygen stable isotope co...
(1994). Mineralogical and textural controls on the organic composition of coastal marine sediments: hydrodynamic separation using SPLITT fractionation. Geochimica et Cosmochimica Acta 58, 879–893. CrossRef Lewan, M.D. (1997). Experiments on the role of water in petroleum formation. Geochimica et...
The chemical composition of the starting glasses is reported as oxides concentration in Supplementary Table1and was determined using a JEOL-JXA8200 electron microprobe at the Bayerisches Geoinstitut (University of Bayreuth, Germany). The chemical analyses were carried out at 15 kV acceleration voltage...
The invention relates generally to a composition and a method for selective removal of a barrier layer in chemical mechanical polishing. In one aspect, the composition for selective removal of a barri
Magma:Molten rock found below the surface of Earth. Metamorphic rock:Rock formed by transformation of preexisting rock through changes in temperature and pressure. Mineral:A naturally occurring, inorganic substance with a definite chemical composition and structure. ...
Five bentonites originating from different environments were selected for the present study: hydrothermal alteration of obsidian perlite glass inside the volcanoes themselves (Providencia and Tribia deposits); alteration of pyroclastic flows in a marine shallow water to lagoonal lacustrine environment (Ib...
respec-tively.The results indicate that all sample with the main chemical composition of SiO2 and Al2O3 are in vitreous state,except two samples(B1 and H3) that are in crystalline state.Tektite and obsidian samples can be distinguished by the chemical composition analysis.The content of iron ...
The measured chemical composition of archaeological ceramics can result from a variety of geological, cultural and taphonomic factors. In the present study, we evaluate the likelihood that elevated barium concentrations in ceramics from the archaeological site of Wom/Aiser, located on the northern ...
Composition 1. Introduction Interest in the application of Raman spectroscopy to geosciences has increased substantially over the last decades. Raman spectroscopic analysis is non-destructive, and it is a relatively straightforward and flexible analytical technique for rapid characterization of geologic materia...