Broken Top

The summit of Broken Top

Broken Top (english broken summit ) is a stratovolcano in the state of Oregon, USA. It is located 5 km southeast of South Sister and about 32 km west of the city Bend in Deschutes County.


In the Pleistocene it was originally a broad shield basaltic andesite. Periodic outbreaks were increasingly siliziumdioxidreicheren magma on, including andesite, dacite and rhyodacite. The latter is a both the dacite and rhyolite similar to the volcanic rocks. You will find Dykes and deposits pyroclastic flows on the slopes of the volcano. Ice Age glaciers have caused severe erosion on the mountain, so the crater is already visible from the outside of the summit area.