Black Rock Desert volcanic field Black Rock Desert volcanic field The Black Rock Desert volcanic field in Millard County, Utah, is a cluster of several volcanic features of the Great Basin such as Pavant Butte and Tabernacle Hill. The field's Ice Springs event was an explosive eruption followed by lava flows that were Utah's most recent volcanic activity (1140–1440 AD). which overlapped the older flows of Pavant Butte. The Pleistocene-Holocene field has been an active tectonic area for approximately 2.7 million years. Within the past 1.5 million years, local volcanism has produced both rhyolitic and basaltic cones from near twenty-four vents from which lava escapes
Lava Creek Tuff tuff layer is approximately . Lava Creek Tuff The Lava Creek Tuff is a tuff formation in Wyoming, Montana and Idaho, United States, created during the Lava Creek eruption around 630,000 years ago, which formed the Yellowstone Caldera. The Lava Creek Tuff is distributed in a radial pattern around the caldera and is formed of of ignimbrites. The tuff has been exposed by erosion at Tuff Cliff along the Gibbon River. Lava Creek Tuff ranges in color from light gray to pale red in some locales. Rock texture of the tuff ranges from fine-grained to aphanitic and is densely welded.