منابع مشابه
Potassian Zirconium and Titanium Silicates and Strontian Cerian Perovskite in Lamproites from the Leucite Hills . Wyoming
The groundmass of lamproites from Middle Table Mountain, Leucite Hills, Wyoming, is characterized by the presence of potassium zirconium silicates and Sr{e-rich perovskite. Two intimately intergrown K-Z silicates of differing Ti content are recognizable by cathodoluminescence t chniques. Both are similar in composition to wadeite. Intergrown with these minerals is a phase having the composition...
متن کاملIsotopic analysis of mineral phases to unravel the origin of altered volcanic rocks: an example from the Leucite Hills lamproites
Study of lamproites from Leucite Hills, Wyoming, indicates that the isotopic compositions of some specimens have been modified due to the alteration and/or the presence of secondary carbonate impurities within the whole rocks. Leachate test shows that while phlogopite lamproites are not affected by secondary processes, the transitional madupitic lamproites from Middle Table Mountain and on...
متن کاملOrigin and Source Evolution of the Leucite Hills Lamproites: Evidence from Sr–Nd–Pb–O Isotopic Compositions
Whole-rock major and trace element and O, Sr, Nd and Pb isotopic data are reported for 3.0–0.89 Ma lamproites from the Leucite Hills, Wyoming, USA. The two main groups of lamproites, madupitic lamproites and phlogopite lamproites, are geochemically distinct and cannot be related to one another by either fractional crystallization or crustal contamination. It seems likely that the geochemical di...
متن کاملThe effect of cesium-containing leucite additions on the thermal and mechanical properties of two leucite-based porcelains.
It has been demonstrated that a Cs(2)O-stabilized leucite porcelain was susceptible to a stress-induced phase transformation, but toughening was not observed.1 It was hypothesized that if Cs(2)O-stabilized leucite core particles were added to a cesium-free matrix porcelain, selected or designed to enhance the toughening mechanism, toughening would occur. A commercial porcelain (VP) and a synthe...
متن کاملthe effect of taftan pozzolan on the compressive strength of concrete in the environmental conditions of oman sea (chabahar port)
cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...
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ژورنال
عنوان ژورنال: Geological Society of America Bulletin
سال: 1896
ISSN: 0016-7606,1943-2674
DOI: 10.1130/gsab-8-169