Figure 8. Trace elements in organic-carbon-rich rocks can be leached from
outcrops or from the subsurface where these rocks are in contact with
groundwater. Both gamma-ray profiles of outcrops and gamma-ray logs in
oil wells can provide a means for mapping selenium content in the Monterey
Formation and possibly other rock units.
http://geology.wr.usgs.gov/wreg/env/block.html
Contact: Margaret A. Keller (mkeller@usgs.gov)
Western Region Energy Group–Environmental Studies
Modified: July 31,
2002
