Results 81 to 90 of about 5,229 (211)
Petrogenesis of Mount St. HElens dacitic magmas
Journal of Geophysical Research: Solid Earth, 1987 The most frequent and voluminous eruptive products at Mount St. Helens are dacitic in composition, although a wide variety of magma types (basalt to rhyodacite) is represented. To address the petrogenesis of the dacites, we present major and trace element analyses of samples of pumice clasts and dome or flow lavas erupted during the past ∼40,000 years.
Diane R. Smith, William P. Leeman
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Petrology and geochemistry of volcanic rocks of Cheshmeh Khuri and Shekasteh Sabz areas, Khur, northwest of Birjand [PDF]
پترولوژی, 2016 Khur area is located in east of Iran and northwest of Birjand. The area comprises outcrops of Eocene to Oligocene volcanics with basaltic andesite to rhyolite composition, which were intruded by subvolcanic and intrusive bodies of granodiorite to gabbro.
Maryam Javidi Moghaddam +4 more
doaj
Journal of Economic Geology, 2010 Sakhtehesar mountain is located in Urumieh-Dokhtar magmatic belt and is composed of volcanic and subvolcanic rocks (Pliocene andesite to dacite) which intruded the volcanics and pyroclastics of Paleocene age.
Farimah Ayati, Saeed Mahdevari
doaj +1 more source
Titanomagnetite Rims on Hornblende Phenocrysts in Intermediate Subvolcanic Intrusions, Torud–Ahmad Abad Magmatic Belt, Iran: Examination of Devolatilization and Oxidation Processes [PDF]
LithosphereMafic to felsic adakitic intrusive and extrusive rocks in the Torud–Ahmad Abad magmatic belt occur south-southeast of Shahrood (north of the Central Iran Zone).
Fazilat Yousefi +2 more
doaj +1 more source
, 2016 Biological CH4 is produced by the process of syntrophy between fermenters and methanogens. CH4 from biological waste products is produced by complex syntrophic systems, which additionally include aerobes and facultative anaerobes jointly working to ...
Kensuke Igarashi (2814925) +1 more
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The relationship between dacite and granodiorite in Victoria
, 1923 (Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.
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K-Ar ages of hornblendes in andesite and dacite from the Cretaceous Kanmon Group, Southwest Japan [PDF]
, 1993 New K-Ar ages of hornblende in volcanic rocks from the type localities of the Shimonoseki Subgroup, upper half of the Kanmon Group are presented. The obtained ages are 105.2±3.3 Ma for andesite and 106.7±3.3 Ma for dacite.
Nakajima, Tsukasa +2 more
core
, 2011 We report the first U-Pb baddeleyite/zircon date for a felsic volcanic rock from the Parana Large Igneous Province in south Brazil. The new date of 134.3 +/- 0.8 Ma for a hypocrystalline Chapeco-type dacite from Ourinhos (northern Parana basin) is an ...
Valdecir de Assis Janasi +5 more
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, 1992 Approximately 10-15 vol% of the Neogene Hoyazo dacite consists of Al-rich restite rock inclusions (A12O3 = 20–45%) and monocrystal inclusions derived therefrom.
H. P. Zeck
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Experimental Constraints on Dacite Pre-eruptive Magma Storage Conditions beneath Uturuncu Volcano
, 2014 Cerro Uturuncu is a long-dormant, compositionally monotonous, effusive dacitic volcano in the Altiplano-Puna Volcanic Complex (APVC) of SW Bolivia.
Hickey, James +8 more
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