Devils Garden volcanDevils Garden volcanic field in central Oregon, east of the Cascade Range, is the NW-most of a group of 3 young basaltic lava fields SE of Newberry volcano. It covers 117 sq km and consists of fissure vents and lava flows.
Introduction:The lava flows from Devils Garden are overlapping pahoehoe lavas with their typical twisted shapes (hence, their name). They erupted from fissure vents, visible as spatter ramparts and cones, located at the NE part of the field.
The lava was extremely fluid and spread quickly into a nearly flat surface surrounding several large kipukas (islands) of older rocks. The lavas are only about 0.5 m thick near the vent, and up to 5 m in distal areas. Their total volume is about 1.2 km3.
The age of the Devils Garden lava flows is unknown, but they are older than the underlying Mazama Ash (6800 years old) but still look fresh and are mostly unvegetated. Literature cites them to be either about 10,000 years (Sarna-Wojciki et al. 1983) or about 20,000 years old (Chitwood 1994).
Sources / references:
- GVP: www.volcano.si.edu/world/volcano.cfm
- Sarna-Wojcicki A M, Champion D E, Davis J O, 1983. Holocene volcanism in the conterminous United States and the role of silicic volcanic ash layers in correlation of latest Pleistocene and Holocene deposits. In: Wright H E (ed) Late-Quaternary Environments of the United States, Minneapolis: Univ Minnesota Press, 2: 52-77
- Chitwood L A, 1994. Inflated basaltic lava--examples of processes and landforms from central and southeast Oregon. Oregon Geol, 56: 11-21
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