The Arizona Geological Survey has just released a new paper: Site Investigation of Tributary Drainages to the San Pedro River, Arizona (Open-file Report OFR-15-02) which is available for free download at: http://repository.azgs.az.gov/uri_gin/azgs/dlio/1724
The paper begins:
In late 2013 the Arizona Geological Survey (AZGS) partnered with the Arizona Department of Water Resources (ADWR) to investigate sedimentary relationships at numerous sites along the San Pedro River in southeastern Arizona. This project supplemented previous work along the San Pedro River. In 2007, AZGS conducted surficial geologic mapping along the San Pedro River, Aravaipa Creek, and the Babocomari River. These maps and a report are available in AZGS DM-RM-1.2. The goal of the 2013 project was to conduct site investigations along the San Pedro River to determine whether sedimentary relationships between San Pedro River and tributary alluvium are accurately represented by their mapped location on the surface. This document includes a brief summary and description of sites along the San Pedro River visited by AZGS geologists in late 2013 and early 2014.
The report describes the geology of 39 sites with text, photos, and maps.