[2] The volcano is composed of a type of volcanic rock called olivine tholeiitic basalt.

[3] The volcano consists of lava flows radiation from the summit, which has a small pyroclastic cone and a large filled crater.

Several smaller craters, formed late in the eruption, are located on the summit and northeast flank of the volcano.

[4] The northern part of the cone includes xenoliths, pieces of surrounding rock caught up in the eruption and carried to the surface.

These are partially melted sandstone, likely of the Santa Fe Group sediments on which the volcano sits.