Results 151 to 160 of about 322 (183)
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Geology, 1987
Mesozoic metavolcanic and metasedimentary rocks in the northern White Mountains, eastern California and western Nevada, are separated from lower Paleozoic and Precambrian rocks by Jurassic and Cretaceous plutons. The large stratigraphic hiatus across the plutons is called the Barcroft structural break. Recent mapping and new U/Pb zircon ages of 154 +3/−
Hanson, R. Brooks +2 more
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Mesozoic metavolcanic and metasedimentary rocks in the northern White Mountains, eastern California and western Nevada, are separated from lower Paleozoic and Precambrian rocks by Jurassic and Cretaceous plutons. The large stratigraphic hiatus across the plutons is called the Barcroft structural break. Recent mapping and new U/Pb zircon ages of 154 +3/−
Hanson, R. Brooks +2 more
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Geochemistry of the Archaean Metavolcanic Rocks of Kolar and Hutti Gold Fields, Karnataka, India
Journal Geological Society of India, 1979Abstract Geochemical data on Archaean goldfields metavolcanics (2.7 b. yrs) have been plotted on major and minor element discriminant diagrams to define the magma type and to formulate the tectonic environment model for the origin of these ancient volcanic rocks.
Iyer, GVA, Vasudev, VN
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Soils on igneous and metavolcanic rocks in the Sonoran Desert of Baja California, Mexico
Geoderma, 1992Soils were examined on the widespread volcanic, plutonic and metavolcanic rocks within the Sonoran Desert of Baja California. In order to focus on in situ weathering and pedogenesis, most of the soils studied were on stable, nearly level summits. The combination of summit landscape positions and the aridic moisture regime tended to yield shallow soils,
R.C. Graham, E. Franco-Vizcaino
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Geochemistry and significance of metavolcanic rocks from the Bou Azzer-El Graara ophiolite (Morocco)
Precambrian Research, 1991Abstract The Bou Azzer-El Graara ophiolite has been interpreted as oceanic or backarc crust overlain by a calc-alkalic arc sequence or as a composite forearc and accretionary melange. Seventy-nine new major and trace element whole-rock analyses of the metavolcanic rocks from throughout the complex support the latter interpretation.
D.D. Naidoo +3 more
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The origin of metavolcanic and associated argillaceous rocks at Island Bay, Wellington, New Zealand
New Zealand Journal of Geology and Geophysics, 1985Abstract The alternating greywacke-argillite turbidite beds exposed on the eastern side of Island Bay, Wellington, New Zealand, belong to the Torlessia fossil zone of the Torlesse Supergroup. They were deposited in a deep-water marine environment. Subsequent reworking by bottom currents has in places formed contourites.
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Earth and Planetary Science Letters, 1979
Abstract Rubidium, Sr, U, Th and Pb concentrations and Sr and Pb isotope data are presented for a suite of Precambrian metavolcanic rocks cropping out in the lower Orange River region of southern Africa. Good agreement between total rock Rb-Sr, Th-Pb and Pb/Pb ages obtained indicates an extrusion age of 1996 ± 15Ma .
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Abstract Rubidium, Sr, U, Th and Pb concentrations and Sr and Pb isotope data are presented for a suite of Precambrian metavolcanic rocks cropping out in the lower Orange River region of southern Africa. Good agreement between total rock Rb-Sr, Th-Pb and Pb/Pb ages obtained indicates an extrusion age of 1996 ± 15Ma .
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Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars
Science, 2022Ken Farley +2 more
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