Black Butte is a group of overlapping dacite domes about 13 km (8 mi) west of Mount Shasta. It erupted during the Holocene. The extrusion of the domes about 9,500 years ago was accompanied by the formation of pyroclastic flows, which extended more than 10 km (6.2 mi) south and 5 km (3.1 mi) north of the domes and covered an area of about 45 km2 (17.4 mi2).
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