Digital database of geologic units, contacts, and faults for Mineral Resource Potential Map of the Turtle Mountains Wilderness Study Area, San Bernardino County, California (U.S. Geological Survey Bulletin 1713-B, 1988, Plate 1)

This map geodatabase digitally represents the general distribution of bedrock geologic map units in the Turtle Mountains area, California, as portrayed in Plate 1 of USGS Bulletin 1713-B, Mineral resources of the Turtle Mountains Wilderness Study Area, San Bernardino County, California (1988), https://doi.org/10.3133/b1713B. The map covers parts of the Rice, Turtle Mountains, and Savahia Peak 15’ quadrangles at 1:48,000 scale. Plate 1 is titled Mineral resource potential map of the Turtle Mountains Wilderness Study Area, San Bernardino County, California. The current database represents the geologic map base of Plate 1, but does not include mines, prospects, and mineral-potential evaluations that Plate 1 also portrays. The geodatabase includes geologic units of Proterozoic, Mesozoic, Tertiary, and Quaternary age, as well as dikes and faults.

As described in Bulletin 1713-B, the mapped rocks record a long and complex geologic history beginning nearly two billion years ago. In Early Proterozoic time, sedimentation and volcanism were followed by plutonism and high-grade regional metamorphism. More plutons (and, subsequently, dikes) were intruded in Middle Proterozoic time. After a long period of geologic stability, the rocks were intruded by plutons and dikes during the Cretaceous. Volcanism, shallow intrusion, and pervasive normal faulting occurred during the Miocene. Since the Miocene, erosion has resulted in the formation of alluvial aprons and pediment veneers on the range flanks.

When using these digital data derived from an earlier publication please also cite the original work:

Howard, K.A., Nielson, J.E., Simpson, R.W., Hazlett, R.W., Alminas, H.V., Nakata, J.K., and McDonnell Jr., J.R., 1988, Mineral resources of the Turtle Mountains Wilderness Study Area, San Bernardino County, California: U.S. Geological Survey Bulletin 1713-B, 1 sheet, scale 1:48,000, Plate 1, https://doi.org/10.3133/b1713B