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Showing 1 to 8 of 8 for “"lamprophyre"”.
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Geochemistry of Variscan lamprophyre magmatism in the Saxo-Thuringian Zone
Lamprophyres are mantle-derived magmatic rocks, commonly occurring as dikes. They are readily identified from their field setting, petrography, chemical and mineralogical composition. These rocks not only provide important information on melting processes in the mantle, but also on geodynamic …
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Petrology of the Cenozoic igneous rocks of the Tinton district, Black Hills, South Dakota - Wyoming
… trachyte porphyry, an alkalic ring dike complex, lamprophyre dikes and intrusive breccia.</p> <p>Precambrian rocks are represented by a sequence of metapelites thst have been intruded by metabasite and granitic pegmatite dikes. The schistosity of the metapelites strikes NNW with a consistent …
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Petrology and Geochemical Evolution of the East Hill Suite of the Mont Saint-Hilaire Alkaline Plutonic Complex
… its own, geochemically, consistent with typical lamprophyre petrogenesis. Whole-rock geochemistry of the East Hill suite shows moderate silica content but highly alkaline rocks, enriched in Mn, Zn, Zr, Y, and Ce. Chlorine and sulfur are important and present in abundant secondary sodalite and …
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Petrography of Four Rock Units Exposed in the Campbell Red Lake Mines, Ontario
… presumed to be igneous in origin and intruded by lamprophyre, quartz-feldspar porphyry, and grey dikes. Samples of the four rock units were taken from the mine and analyzed by macroscopic, microscopic, and x-ray diffraction techniques. </p><p>Field and laboratory observations suggest that the …
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Megacryst suite from the Salpeterkop carbonatite complex, Sutherland, Northern Cape, South Africa: an in-depth geochemical study
… results suggest that the Salpeterkop ultramafic lamprophyres are genetically related the the SPKC megacryst suite, however, the calculated parent melt to the megacryst appears to have mixed with a HIMU component. These findings primarily affect higher Mg-number megacrysts, suggesting that this …
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The geochemistry and petrogenesis of the Saltpeterkop carbonatite complex near Sutherland, Northern Cape, South Africa
… trachyte, olivine melilitite and ultramafic lamprophyre. This thesis provides the first detailed petrographic and geochemical description of these rocks (e.g., major and trace elements) and attempts to explain several aspects of their petrogenesis. The olivine melilitites and ultramafic …
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The petrogenesis and geochemistry of the Namaqualand olivine melilitite pipe cluster, western South Africa
… of hundreds of diatremes containing ultramafic lamprophyre and kimberlite in addition to the rock types named above. The NBW lineament appears to be an ageprogressive feature, with ages increasing toward the northeast at a rate and direction roughly consistent with Late Cretaceous to Cenozoic …
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Mineralogical characterization and paragenesis of the Cripple Creek deposit, Colorado
… that range in composition from phonolite to lamprophyre. The deposit has historic production of >24 Moz of gold, making it the third most productive gold deposit in the United States. Most of this production came from underground mining operations that started with the discovery of the …