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Obsidian (/ ə b ˈ s ɪ d i. ən, ɒ b-/ əb-SID-ee-ən ob-) [5] is a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. [6] Obsidian is produced from felsic lava, rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium.
Olorgesailie is a geological formation in East Africa, on the floor of the Eastern Rift Valley in southern Kenya, 67 kilometres (42 mi) southwest of Nairobi along the road to Lake Magadi. It contains a group of Lower Paleolithic archaeological sites. [1] Olorgesailie is noted for the large number of Acheulean hand axes discovered there that are ...
Obsidian projectile point.. Obsidian is a naturally formed volcanic glass that was an important part of the material culture of Pre-Columbian Mesoamerica.Obsidian was a highly integrated part of daily and ritual life, and its widespread and varied use may be a significant contributor to Mesoamerica's lack of metallurgy.
From the 1950s to the 1990s, O'Keefe argued for the lunar origin of tektites based upon their chemical, i.e. rare-earth, isotopic, and bulk, composition and physical properties. [ 5 ] [ 25 ] Chapman used complex orbital computer models and extensive wind tunnel tests to argue that the so-called Australasian tektites originated from the Rosse ...
Obsidian Cliff, also known as 48YE433, was an important source of lithic materials for prehistoric peoples in Yellowstone National Park near Mammoth Hot Springs, Wyoming, United States. The cliff was named by Philetus Norris, the second park superintendent in 1878. [4] It was declared a National Historic Landmark in 1996. [1][3]
The Salton Buttes are a group of volcanoes in Southern California, on the Salton Sea. They consist of a 7-kilometer (4.3 mi)-long row of five lava domes, named Mullet Island, North Red Hill, Obsidian Butte, Rock Hill and South Red Hill. They are closely associated with a fumarolic field and a geothermal field, and there is evidence of buried ...
Teotihuacan (/ t eɪ ˌ oʊ t iː w ə ˈ k ɑː n /; [1] Spanish: Teotihuacán, Spanish pronunciation: [teotiwa'kan] ⓘ; modern Nahuatl pronunciation ⓘ) is an ancient Mesoamerican city located in a sub-valley of the Valley of Mexico, which is located in the State of Mexico, 40 kilometers (25 mi) northeast of modern-day Mexico City.
Rhyolite (/ ˈraɪ.əlaɪt / RY-ə-lyte) [1][2][3][4] is the most silica -rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral assemblage is predominantly quartz, sanidine, and plagioclase.