Geologic Map of the Somerton 7 1/2' Quadrangle, Yuma County, Arizona

The map area is comprised entirely of late Cenozoic sediments. The map area can be divided into two geomorphic settings. The NW half of the quadrangle includes Yuma Valley and consists of Holocene Colorado River deposits. Approximately 12m (40 feet) above the river valley is Yuma Mesa which occupies the SE half of the quadrangle and is composed of late Pleistocene Colorado River sediments called the Chemehuevi Formation.These GIS data adhere to the standard format supported by the US Geological Survey's National Cooperative Geologic Mapping Program (NCGMP09). NCGMP09 recommends distributing geologic map data using the proprietary ESRI File Geodatabase format. We follow this convention, but also provide open-source geojson and csv data as part of this collection.Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact azgs-info@email.arizona.edu