Four Craters Lava Field
|Four Craters Lava Field|
Craters of the aptly named Four Craters Lava Field are seen here from the NW on Green Mountain.
|Elevation||4,924 ft (1,501 m)|
|Location||Lake County, Oregon, U.S.|
|Age of rock||Pleistocene|
|Last eruption||< 50,000 years ago|
Four Craters Lava Field is a basaltic volcanic field located south east of Newberry Caldera in the U.S. state of Oregon. The volcanic field covers about 30 square kilometers. Four Pleistocene cinder cones are the source of the flows in the field and are aligned along a fissure trending N 30° W. The cones rise 75 to 120 meters above the flows and the distance between the northern most and southern most cones is about 3.5 kilometers.
Closely related to the Four Craters lava field is Crack-in-the-Ground located at the southwest corner of the field. The eruptions from the field were accompanied by a slight sinking of the older rock surface. This shallow, graben-like sink is about 3 kilometers wide and extends to the south into an old lake basin. Crack-in-the-Ground marks the western edge of this small, volcano-tectonic depression and is nearly 9 meters deep and over a meter wide. The crack is the result of a tension fracture along a hingeline produced by the drapping of Green Mountain lava flows over the edge of upthrown side of the concealed fault zone.
This article incorporates public domain material from the United States Forest Service document "Deschutes & Ochoco National Forests - Crooked River National Grassland". (archived)
- "Four Craters Lava Field". Global Volcanism Program. Smithsonian Institution. Retrieved 2008-05-12.
- "Four Craters Lava Field". Geographic Names Information System. United States Geological Survey. Retrieved 2014-12-29.
- "Oregon Volcanoes - Four Craters Flows". Deschutes & Ochoco National Forests - Crooked River National Grassland. United States Forest Service. 2003-12-24. Archived from the original on 2010-11-09. Retrieved 2008-05-12.
- Peterson, Norman V.; Edward A. Groh (September 1964). "Crack-In-The-Ground, Lake County, Oregon" (PDF). The Ore Bin (Portland, Oregon: State Of Oregon - Department of Geology and Mineral Industries) 26 (9): pp. 158–166. Retrieved 2008-08-21.
- Peterson, Norman V.; Edward A. Groh (March 1963). "Recent Volcanic Landforms In Central Oregon" (PDF). The Ore Bin (Portland, Oregon: State Of Oregon - Department of Geology and Mineral Industries) 25 (3): pp. 33–45. Retrieved 2008-08-21.