نتایج جستجو برای: volcanic rocks
تعداد نتایج: 34325 فیلتر نتایج به سال:
logues rocks during entry into the Earth’s atmosphere F. Foucher, F. Westall , J.-M. Bény , F. Brandstätter , and R. Demets , 1 Centre de Biophysique Moléculaire, UPR CNRS 4301, Orléans, France ([email protected]), 2 Institut des Sciences de la Terre d’Orléans, UMR CNRS 6113, Orléans, France, 3 Naturhistorisches Museum, Burgring 7, 1010 Wien, Austria, 4 European Space & Technolog...
Hamyerd iron deposit is located about 74 km north east of Semnan, in the Jam area. This area is situated in the northern part of Central Iran structural zone. The outcrops are Middle-Eocene volcanic and pyroclastic rocks with andesite to andesite-basalt and tuff composition, which are intruded by some intrusive bodies of monzonite to monzodiorite composition in this area. Iron mineralization is...
Newly discovered xenoliths within Pliocene and Quaternary intermediate volcanic rocks from southern Peru permit examination of lithospheric processes by which thick crust (60–70 km) and high average elevations (3–4 km) resulted within the Altiplano, the second most extensive orogenic plateau on Earth. The most common petrographic groups of xenoliths studied here are igneous or meta-igneous rock...
bentonite deposits of economic interest are widespread in tashtab mountains (khur), east of isfahan province, iran. several bentonite deposits have been developed in this area as a result of eocene volcanic alteration. these deposits are classified as khur bentonite horizon. xrd analyses reveal that alteration products consist of na-montmorillonite, kaolinite, quartz, calcite, and crystobalite....
salafchegan-khorhe volcanic rocks are exposed within urumieh-dokhtar magmatic belt. different kinds of volcanic and subvolcanic rocks of calc-alkaline to alkaline character have been reported throughout this magmatic belt. since, isotopic investigations are very useful for detection of magma petrogenesis and because no isotopic studies have been done in this area, so a geochemical and isotopic ...
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 study area is located in North-East of Lut block, and in Basiran Geological Quadrangle Map (1:100000).Tertiary intrusive-subvolcanic rocks intruded Paleocene limestone and formed skarn and Iron mineralization. Petographic studies show that rocks are Hbl-diorite porphyry, Hbl-qtz- diorite porphyry, Px- diorite porphyry, Hbl-px- diorite porphyry, Hbl-diorite and Bt-diorite. These rocks are s...
85 The physiography of the area is dominated by glaciated landforms carved in gneiss of the Fiordland Complex. The gneiss is generally dioritic, with gradations to quartzo-feldspathic and amphibolitic varieties, and is cut by mainly barren pegmatite veins; epidote is abundant. The rocks commonly show signs of post-consolidational shearing and crushing. There is a well defined zone of strongly c...
Volcano monitoring uses knowledge of volcanic processes and extensive data gathering to analyze areas of volcanic activity. The main goal is to learn the nature of the volcano, the magmatic processes occurring, and the likelihood of a future eruption. Volcano monitoring centers around three aspects of volcanic processes: ground deformation, seismic activity, and gas emissions. These techniques ...
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