نتایج جستجو برای: post collision volcanic rocks
تعداد نتایج: 484133 فیلتر نتایج به سال:
________________________________________ Introduction __ ___________________________________ Area covered.__________________________________ Aeromagnetic survey.___________________________ Gravity survey.________________________________ Acknowledgments--.. __1________________________ Geology __ __ ____________ _ Rock units_____________________________________ Carboniferous and older rocks._____...
توالی سنگشناسی و ویژگیهای ژئوشیمیائی سنگهای آتشفشانی فاز دوی پالئوژن در منطقه دیلمان، البرز باختری
Deylaman area lies on Paleogene volcanic rocks in Western Alborz near the border between Central and Western Alborz structural zones. The succession of Paleogene rocks in the area is comprised of three separate phases each of which representing one stage of volcanic events. The main purpose of this paper is to study the lithologic sequence and geochemical characteristics of phase two volcanic r...
arghash – ghasem-abad area in ne iran is located in the rim of the sabzevar structural zone. tertiary outcrops include granite and quartz monzodiorite porphyry associated with dacite and andesite volcanic rocks. in the study area, quartz gabbro and quartz monzodiorite dykes intruded the older rocks. granite and volcanic rocks host au-sb-bearing quartz-calcite veins. mineralized veins are mainly...
The study area is situated within the Lut Block 50 Km northeast of Ferdows. The oldest exposed rocks are Cretaceous limestone. Kerman conglomerate cover the limestone. Dacite-rhyodacite lava and pyroclastic rocks erupted over Kerman conglomerate. Volcanic activities took place at different time in Tertiary. The composition ranges between trachyandesite, andesite, andesite-basalt and rhyolitic ...
The study area is located in the east of Ahar town in Eastern Azerbaijan Province and is part of the Ahar-Arasbaran Cenozoic magmatic belt of NW Iran. The geological units of the Eocene age are volcanic rocks with andesite, latite - andesite and basaltic andesite composition. Khankandi and Useflu Oligocene intrusive bodies intruded in the volcanic rocks and caused widespread alteration and copp...
The origin and life cycle of ocean islands have been debated since the early days of Geology. In the case of the Canary archipelago, its proximity to the Atlas orogen led to initial fracture-controlled models for island genesis, while later workers cited a Miocene-Quaternary east-west age-progression to support an underlying mantle-plume. The recent discovery of submarine Cretaceous volcanic ro...
The role of the subducting lithospheric slab in the genesis of mantle-derived (primitive) magmas is investigated through a study of volcanic rocks formed in the tectonically strike-slip–dominated western Aleutian arc. Two types of chemically and petrologically distinctive primitive andesites have been found among the Miocene– late Pleistocene–age volcanic rocks in the western Aleutians. These a...
Introduction: Recently published reports on chemical and physical properties of Mars sediments indicate that diagenetically altered volcanic rocks were reworked by sedimentary processes [1]. Furthermore, compositional and petrographic aspects of sediments show varying degrees of elemental enrichment as well as complex interaction between the minerals in partially saturated or saturated conditio...
rocks of the Stuhuni and King Salmon Groups; a pre-.Middlm: Triassic unconformity is found througbmt the North American Cordillera (Read and Okulitch, 1977, Siberling, 1973:. In the Stikine Terrane, late Triassic volcanic rocks ar: dominantly fragmental andcommonly alkalic. Based on bul:: rock chemistry, both extensional, ba:k-arc, and Fore-ar: tectonic settings have been suggested tor these r...
The granite-gneiss body of Abadchi area (vicinity of Zayandeh-Rud dam) is a part of Sanandaj-Sirjan tectonic zone. The mineralogical composition of the granite- gneisses contains quartz, K-feldspar, plagioclase, biotite and muscovite and minor minerals of opaque, zircon, amphibole and allanite. The granite-gneiss rocks have been influenced by deformation dynamics and weakly Na-metazomatism. Ge...
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