AZGS released a new surficial geologic map of the Empire Ranch quadrangle in the Santa Rita Mountains, south of Tucson. The 1:24,000 scale map by AZGS geologist Joe Cook is posted online in our digital document repository. The map covers piedmont, and stream channel and alluvium deposits of the quadrangle. The mapping was done with cooperative funding from the USGS under the Statemap program.
The Empire Ranch quad covers part of the area of the proposed Rosemont copper mine. We completed the bedrock part of this and the adjacent Helvetia quad last year and provided them the US Forest Service to provide insights into geologic issues affecting the mine project EIS.