Search results
Results From The WOW.Com Content Network
Obsidian has also been found in Gilat, a site in the western Negev in Israel. Eight obsidian artifacts dating to the Chalcolithic Age found at this site were traced to obsidian sources in Anatolia. Neutron activation analysis (NAA) on the obsidian found at this site helped to reveal trade routes and exchange networks previously unknown. [52]
Geologic map of the Sonoma Volcanics. The Sonoma Volcanics are a geologic formation of volcanic origin that is widespread in Napa and Sonoma counties, California.Most of the formation is Pliocene in age and includes obsidian, perlitic glass, diatomaceous mud, pyroclastic tuff, pumice, rhyolite tuffs, andesite breccias and interbedded volcanic lava flows.
Farther north of these craters are five lava domes, including Deadman Creek Dome, Glass Creek Dome, Obsidian Dome, and Wilson Butte. [11] These domes are composed of gray rhyolite, frothy pumice, and black obsidian. The Inyo volcanic chain extends into Long Valley Caldera but is not related to the caldera's volcanism. [8]: 290
Before Obsidian Butte was emplaced and thus became available for obsidian production, people in the region used obsidian from the Coso volcanic field; [44] this trend away from Coso towards Obsidian Butte was recognized even before the exact timing of the Obsidian Butte eruption was known. [42] How the magmas are formed is controversial.
Apache tears are rounded pebbles of obsidian or "obsidianites" composed of black or dark-colored natural volcanic glass, usually of rhyolitic composition and bearing conchoidal fracture. Also known by the lithologic term marekanite , this variety of obsidian occurs as subrounded to subangular bodies up to about 2 in (51 mm) in diameter, often ...
In fact, the mountains are named for the numerous deposits of obsidian found on their slopes. [ 2 ] [ 8 ] [ 24 ] There is a wide variety of high-quality obsidian found in the area including jet black, brown, green, red fire, pumpkin, mahogany, midnight lace, rainbow, gold sheen, silver sheen, and snowflake as well as several double flow varieties.
A rarely seen deep sea fish resembling a serpent was found floating dead on the ocean surface off the San Diego coast and was brought ashore for study, marine experts said. The silvery, 12-foot ...
The major volcanoes of the Cascade Range are fed from heat generated as tectonic plates dive below North America.. All rock now exposed in the area of the park is volcanic, and unconformably overlies much older sedimentary, metamorphic and igneous rock, [6] which was formed during the hundreds of millions of years when the Lassen region underwent repeated uplifting to form mountains, only to ...