Search results
Results From The WOW.Com Content Network
Rhyolite is common along convergent plate boundaries, where a slab of oceanic lithosphere is being subducted into the Earth's mantle beneath overriding oceanic or continental lithosphere. It can sometimes be the predominant igneous rock type in these settings. Rhyolite is more common when the overriding lithosphere is continental rather than ...
Llanite is a porphyritic rhyolite with distinctive phenocrysts of blue quartz (a rare quartz color) and perthitic feldspar (light grayish-orangeish). The brown, fine-grained groundmass consists of very small quartz, feldspar, and biotite mica crystals.
The mechanical properties of the rhyolite on Mount Kineo exhibits the physical properties of flint and was used extensively by indigenous peoples to make arrowheads and implements and thus, has often been referred to as "Kineo flint" in literature; but this term misleads by implication that the rhyolite is a cryptocrystalline form of the ...
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite. [1] Phenocrysts are sodic sanidine with minor albite and bipyramidal quartz. [2] The blue colour is caused by very small crystals of riebeckite or arfvedsonite. [3] The 1903 eruption of Changbaishan volcano in northeast China erupted comendite pumice. [4]
The rhyolite tuff member is the lowest stratigraphic exposure of the Newbury Volcanic Complex. This member is made up of glassy fragments of rhyolitic tuff that is heavily sheared and is crudely held together and is about 6 m in thickness and yellowish-brown to brownish-gray in color.
Rhyolite Ridge is the only known lithium-boron deposit in North America and one of only two known such deposits in the world. There is currently only one lithium producing mine in the U.S ...
The calc-alkaline magma series is one of two main subdivisions of the subalkaline magma series, the other subalkaline magma series being the tholeiitic series. A magma series is a series of compositions that describes the evolution of a mafic magma, which is high in magnesium and iron and produces basalt or gabbro, as it fractionally crystallizes to become a felsic magma, which is low in ...
The ancient Ballena River brought rhyolite-gravel, or "Poway" clasts, from a region in present-day Sonora, Mexico to the Pacific Ocean. Its sediments deposited into an alluvial fan–submarine canyon–submarine fan complex extending for miles offshore. Remnants of submarine fan facies outcrops are found as far west as the northern Channel Islands.