Lava Beds National Monument Butte is just outside the boundary of the monument, the Callahan flow is in Lava Beds and is the youngest flow in the monument. Spatter cones are built out of thicker lava. The lava is thrown out of the vent and builds, layer by layer, a chimney surrounding the vent. Fleener Chimneys and Black Crater are examples of spatter cones. Roughly ninety percent of the lava in the Lava Beds Monument is basaltic. There are primarily two kinds of basaltic lava flows: pahoehoe and 'a'a. Pahoehoe is smooth, often ropy and is the most common type of lava in Lava
Lava picture). Block lava flows are typical of andesitic lavas from stratovolcanoes. They behave in a similar manner to ʻaʻā flows but their more viscous nature causes the surface to be covered in smooth-sided angular fragments (blocks) of solidified lava instead of clinkers. Like in ʻaʻā flows, the molten interior of the flow, which is kept insulated by the solidified blocky surface, overrides the rubble that falls off the flow front. They also move much more slowly downhill and are thicker in depth than ʻaʻā flows. Lava domes and coulées are associated with felsic lava flows ranging from dacite to rhyolite.