| Marysvale volcanic field | |
| Location: | Utah, United States |
| Map: | USA Utah |
| Coordinates: | 38.5°N -142°W |
| Type: | Volcanic field |
| Age: | Middle Cenozoic |
The Marysvale volcanic field is located in southwestern Utah, United States.
One of the largest volcanic fields in the western United States, the Marysvale straddles the Colorado Plateau-Great Basin transition zone. Most igneous rocks belong to a middle Cenozoic (~32 to 22 million years old) calc-alkaline sequence, although about 5% are related to an upper Cenozoic (23 million years to Holocene) bimodal (basalt and rhyolite) sequence. The Marysvale contains a variety of volcanic features, including stratovolcanoes, calderas, lava domes, and cinder cones.
The field is an example of intraplate volcanism; its earlier deposits are thought to be related to Farallon plate subduction, while the later bimodal assemblage (especially the basalts) have been linked to Basin and Range extension.
| Name | Size | Age | ||
|---|---|---|---|---|
| Monroe Peak Caldera | 20 x 16 km | 38.4833°N -112.0583°W[1] | 23 Ma | |
| Big John Caldera | 10 x 6 km | 38.3182°N -112.3833°W | 24 Ma | |
| Mount Belknap Caldera | 17 x 13 km | 38.4475°N -112.5°W | 19 Ma |