There is no current information on any Holocene eruptions from Brushy Butte, the last known eruption for the Brushy Butte was in the Pleistocene age, and the eruption was considered to be over 10-20 years, this was found based on the different lava flow landforms created and their placement around the interior of the volcano..  Brushy Butte is located in a rifting area and the type of magma that erupted is called tholeiitic basalt; a type of lava that is dark and it contains 45 to 53 percent of silica, rich in iron and magnesium.
There is no current information on any Holocene eruptions from Brushy Butte, the last known eruption for the Brushy Butte was in the Pleistocene era, and the eruption lasted approximately 10-20 years, as determined by the distinctive lava flow landforms created and their placement around the volcano's interior. Brushy Butte is situated in a rift zone and the type of magma that erupted is called tholeiitic basalt; a dark-colored lava rich in iron and magnesium.