نتایج جستجو برای: source rocks
تعداد نتایج: 438306 فیلتر نتایج به سال:
the world wide web becomes very popular recently and plays an influential role in english learning. by burgeoning role of source-based writing as partial fulfillment of tefl courses and vast use of the internet, lack of empirical studies to explore these areas is obvious. this study aimed to explore the effect of the amount of familiarity with the web (internet literacy) on junior english stude...
Hydrogen and oxygen isotope ratios of 500 samples, mainly from granitic plutons, were measured along a 700-km, E-W traverse across the "accreted terranes" of southern British Columbia (latitudes 49ø-52øN). Despite the geological complexity and range of intrusive ages (Late Triassic to Tertiary) and although there are "steps" in the isotopic values at some geologic boundaries (e.g., across the S...
The 10.5 km diameter Bosumtwi crater in Ghana, West Africa, is the most likely source crater for the Ivory Coast tektites, as the tektites and the crater have the same age (1.07 Ma), and there are close similarities between the isotopic and chemical compositions of the tektites and crater rocks. The crater is excavated in 2.1–2.2 Ga old metasediments and metavolcanics of the Birimian Supergroup...
The name Newburg has been applied to a highly permeable zone, 0.3 to 9 m thick, occurring in a granular or vuggy dolomite. The zone occurs in carbonate rocks of Middle to Late Silurian age across much of Ohio. Known also to well drillers as the "Second Water" in the "Big Lime" carbonate sequence, the Newburg zone is a source of hydrocarbons in northeast Ohio, brines in southeast Ohio, and a wid...
Oxygen isotope data are reported for clinopyroxene phenocrysts from volcanic rock samples from Filicudi island, Italy, with the aim of investigating mechanisms of magma evolution and mantle source characteristics in a continental arc volcano. Filicudi rocks range from calc-alkaline basalt to high-K andesite and dacite. Mafic rocks have MgO 6-7 wt%, Mg# 60, Ni < 50 ppm and Cr < 200 ppm, suggesti...
Trachyandesites, trachytes and latites associated with ignimbrite and pyrocalstic rocks, characterized by shoshonitic affinity are the main Plio-Quaternary volcanic rocks in the Sabalan region (Ardabil). Plagioclase, K-feldspar, biotite associated with clinopyroxene and glass are the main constituents of these lavas. Plagioclases are andesine to labradorite while clinopyroxenes have augitic com...
This area is located in Derenjal Mountains, 60Km northwest of Tabas in central Iranian structural zone. The igneous rocks occur as plutonic with composition of olivine-gabbro, gabbro, diorite and monzodiorite in Kalshaneh Formation with Middle Cambrian age and as the extrusive rocks with composition of olivine basaltic lavas in lower part of Niur Formation with Silurian age. Petrographical and ...
Determining oil migration distances from source rocks to reservoirs can greatly help in the search for new petroleum accumulations. Concentrations and ratios of polar organic compounds are known to change due to preferential sorption of these compounds in migrating oils onto immobile mineral surfaces. However, these compounds cannot be directly used as proxies for oil migration distances becaus...
Processes that operate at planetary surfaces have the potential to record a history of planetary evolution in the form of sedimentary rocks. This is important because our experience on Earth shows that sediments and sedimentary rocks are the dominant archive of high-resolution proxies of present and past tectonic, climatic, and biological processes. Our understanding of the evolution of Earth’s...
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