نتایج جستجو برای: calcic and potassic alterations
تعداد نتایج: 16837266 فیلتر نتایج به سال:
The origin of analcite-bearing lavas and potassic volcanic rocks is controversial in the geological record. Two main hypotheses are either primary analcite or replacement pseudomorphous of leucite. Spectacular large (5 cm) euhedral trapezohedra occur as single crystals of analcite in tephriphonolite lavas from Nadik area. Based on the following evidences the large analcite trapezohedra from Nad...
Aim: Many countries import potassic fertilizers due to dearth of K-mineral deposits. Therefore processes to obtain K-nutrient sources from sea bittern were developed by our Institute. The present investigation evaluated the fertilizer potential of three different sea bittern-derived (SBD) potassium forms developed viz., potassium schoenite, potassium nitrate and potassium ammonium sulfate on ma...
Abstract A plagioclase megacryst containing composite crystal-glass inclusions was ejected in a Pliocene basaltic diatreme the Carpathian back-arc basin (Pannonian Basin). The grew from phonolitic melt, relics of which are preserved inclusions. Most pristine melt has undergone substantial compositional resetting by interaction with several batches low-viscosity carbonated, P-rich melilitite inf...
The calcareous rocks in the Takht-e- Soleyman area (NW Iran) crop out in association with a variety of metamorphic rocks including amphibolites, granitic gneisses, pelitic schists and meta-ultramafic rocks. Retrogressive metamorphism of these rocks occurred during decompressional cooling during exhumation. Cummingtonite-bearing rocks resulted from retrogression of the calc-silicates in the area...
Clay mineralogy of paleosols provides more information about Quaternary climatic changes and paleoenvironmental conditions. Clay minerals of an alluvial fan in eastern Isfahan were studied, using x-ray diffraction analysis. Studied paleosols are located on old Qf1 and Qf2 geomorphic surfaces. Qf1 geomorphic surface is older and topographically higher than Qf2. The results of clay mineralogy sho...
Sar-Kuh porphyry copper deposit is located 6 km southwest of the Sar-Cheshmeh copper mine, Kerman Province, Iran. Based on field geology, petrography and fluid inclusions studies, four alteration types have been identified in the Sar-Kuh area. Early hydrothermal alteration formed a potassic zone in the central parts of Mamzar granite/grano-diorite stock and propylitic alteration in its peripher...
Charnockitic rocks form extensive orthogneiss plutons in many granulite terranes and are less commonly found in unmetamorphosed plutons, which have formed in various tectonic regimes. Geochemically, clearly igneous charnockites cover nearly the whole range of granite chemistry, from magnesian to ferroan and from calcic to alkalic. Pyroxenes from unmetamorphosed charnockitic rocks have compositi...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید