Synonymer & Information om | Engelska ordet RHYOLITE

Exempel på hur man kan använda RHYOLITE i en mening

• It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl, and basalt.
• Pillow lavas are commonly of basaltic composition, although pillows formed of komatiite, picrite, boninite, basaltic andesite, andesite, dacite or even rhyolite are known.
• The uranium occurs as veins within quartz monzonite, granite and rhyolite, usually in the form of pitchblende, but also as umohoite, which was first identified at Marysvale.
• Cryptocrystalline tool stones include flint and chert, which are fine-grained sedimentary materials; rhyolite and felsite, which are igneous flowstones; and obsidian, a form of natural glass created by igneous processes.
• Ground stone tools are usually made of basalt, rhyolite, granite, or other cryptocrystalline and igneous stones whose coarse structure makes them ideal for grinding other materials, including plants and other stones.
• Bentonite usually forms from the weathering of volcanic ash in seawater, or by hydrothermal circulation through the porosity of volcanic ash beds, which converts (devitrification) the volcanic glass (obsidian, rhyolite, dacite) present in the ash into clay minerals.
• Mammoth Mountain is composed primarily of dacite and rhyolite, part of which has been altered by hydrothermal activity from fumaroles (steam vents).
• It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite.
• The hills had a religious significance to the Massachusett, who extensively mined rhyolite to make weaponry thought to be imbued with divine strength from the sacred hills.
• Most of the Mono Craters, which make up the bulk of the northern part of the Mono–Inyo chain, are phreatic (steam explosion) volcanoes that have since been either plugged or over-topped by rhyolite domes and lava flows.
• The subvolcanic intrusives are similar in geochemistry to the associated rhyolite volcanics, which they intrude into.
• They are often visible in specimens of obsidian, pitchstone, and rhyolite as globules about the size of millet seed or rice grain, with a duller luster than the surrounding glassy base of the rock, and when they are examined with a lens they prove to have a radiate fibrous structure.
• Lapilli tuffs are a very common form of volcanic rock typical of rhyolite, andesite and dacite pyroclastic eruptions, where thick layers of lapilli can be deposited during a basal surge eruption.
• The canyon below the Lower Yellowstone Falls was at one time the site of a geyser basin that was the result of rhyolite lava flows, extensive faulting, and heat beneath the surface (related to the hot spot).
• The combination of regional extension, which lowers the maximum attainable overpressure on the chamber roof, and a large magma chamber with warm walls, which has a high effective viscoelasticity, may suppress rhyolite dike formation and allow such large chambers to fill with magma.
• This rock is typically of extrusive origin, formed by compaction of fine volcanic ash, and may be found in association with obsidian and rhyolite.
• The volcanic origin of these mountains is evidenced by tholeiite basalt deposits, the numerous hot springs and rivulets in the area, as well as red volcanic rhyolite stone most marked near the two caldera.
• The Pliocene Undu Group in the northeastern portion of the island, consists of breccia, tuff, and flows of rhyolite and dacite overlain by pumiceous strata.
• Most of the volcanoes are basalt cinder cones, but there are also large lava domes consisting of rhyolite and dacite.
• The Harney Basin Volcanic Field is a series of volcanic flows of rhyolite and of tuffs of ash flows in around Burns, Oregon.

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