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Rhyolitic tuff has been used extensively for construction. Obsidian, which is rhyolitic volcanic glass, has been used for tools from prehistoric times to the present day because it can be shaped to an extremely sharp edge. Rhyolitic pumice finds use as an abrasive, in concrete, and as a soil amendment.
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. [1] [2] Rock that contains greater than 75% ash is considered tuff, while rock containing 25% to 75% ash is described as tuffaceous (for example, tuffaceous sandstone). [3]
Tuff – Rock consolidated from volcanic ash; Websterite – Ultramafic and ultrabasic rock – A type of pyroxenite, composed of clinoproxene and orthopyroxene; Wehrlite – Ultramafic rock - An ultramafic plutonic or cumulate rock, a type of peridotite, composed of olivine and clinopyroxene
The Bishop Tuff is a welded tuff which formed 764,800 ± 600 years ago as a rhyolitic pyroclastic flow during the approximately six-day eruption that formed the Long Valley Caldera. [1] [2] [3] Large outcrops of the tuff are located in Inyo and Mono Counties, California, United States. Approximately 200 cubic kilometers of ash and tuff erupted ...
Sandstone, shale, Tuff: Location; Region: Northern Cape, Western, Eastern Cape, KwaZulu-Natal, Free State. Country South Africa: Extent: 145 000 km squared: A simplified geological map of the outcrops of Karoo Supergroup rocks in Southern Africa. The Beaufort Group is represented by the yellow key on the map.
Poison Profits. A HuffPost / WNYC investigation into lead contamination in New York City
The sandstones, claystones, mudstones, conglomerates and tuff were deposited in a fluvial environment. [2] The upper part of formation is laterally equivalent to the Yacimiento El Trébol and Meseta Espinosa Formation and the lower part to the Laguna Palacios , Cañadón Seco and Comodoro Rivadavia Formations .
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