Proposal title: miocene transtensional basin evolution and quaternary development of the amargosa river canyon: geologic mapping in the tecopa 7.5' and part of dumont dunes 7.5' quadrangles,…

The U.S. Geological Survey awarded the University of Memphis a cooperative agreement valued at $147,817 on January 15, 2026, under the National Cooperative Geologic Mapping Program (EDMAP component, CFDA 15.810).

The recipient will conduct geologic mapping and geochronology in the Tecopa 7.5' and part of the Dumont Dunes 7.5' quadrangles in southeastern California. Work will address the Miocene transtensional basin evolution of the China Ranch and Dumont Hills basins and clarify the incision history of the Amargosa River and the drainage of Pleistocene Lake Tecopa. Mapping will constrain the timing and origin of Miocene deposits, their relationship to major regional fault systems, and the age and origin of Quaternary terrace and surficial deposits in southern Amargosa Canyon. A graduate student will lead the mapping effort with assistance from faculty advisor Dr. Larsen and one or more undergraduate students, using Google Earth and field-based methods.

The period of performance runs from January 15, 2026, through June 30, 2028. Place of performance is listed as Texas.

EDMAP is the educational component of the National Cooperative Geologic Mapping Program, partnering with colleges and universities to train the next generation of geologic mappers through hands-on, field-based mentored mapping projects. Student mapping projects may extend up to two years, with separate proposals submitted for each year.

Proposal title: miocene transtensional basin evolution and quaternary development of the amargosa river canyon: geologic mapping in the tecopa 7.5' and part of dumont dunes 7.5' quadrangles, southeastern california project period: 01/15/2026 - 06/30/2028 purpose the proposed project seeks to complete geologic mapping in the southern part of the tecopa 7.5? Quadrangle, california, refining the geologic histories and tectonic development of the miocene china ranch and dumont hills basins, and map geology along a corridor of southern amargosa canyon in the tecopa 7.5? And dumont dunes 7.5? Quadrangles, california, to clarify the incision history of the amargosa river. Two fundamental questions drive this mapping project: 1) how did the miocene transtensional basins evolve and respond to changing tectonic regimes in the middle to late miocene, and 2) how did the drainage of pleistocene lake tecopa and incision of the amargosa river create amargosa canyon? Previous edmapsupported mapping set the stage for the proposed mapping study by addressing structural, stratigraphic and geomorphic relationships between the pleistocene tecopa basin deposits and miocene china ranch basin deposits, as well as defining middle to late pleistocene post-lake tecopa and northern amargosa canyon terrace levels. Geologic mapping of the miocene deposits will seek to better constrain timing and origin of the china ranch and dumont hills basins and determine their relationship to major regional fault systems. Mapping of the quaternary terrace and other surficial deposits in southern amargosa canyon will seek to determine their origin and age and clarify relationships to upstream terraces in the tecopa basin and northern amargosa canyon, and the hydrologic history of the amargosa river. Activities geologic mapping and geochronology will be completed by the graduate student with assistance from DR. Larsen and one or more undergraduate students. The mapping will be completed using google earth and other satellite imagery tools as well as in-field activities each year. The field mapping will utilize paper maps, GPS-based field location data collection and detailed field note descriptions. Data from paper maps will be finalized in the office and compiled in arcgis using the CGS gems geodatabase system. Analytical work will include 40AR/39AR and detrital zircon dating of miocene deposits and optically stimulated luminescence dating of late quaternary deposits. Deliverables and outcomes the graduate student will complete their masters thesis in december 2027 and include data and analysis of the mapping results. In december 2027, DR. Larsen will send to the USGS edmap program director and california geological survey mapping program supervisor the project report and digital geologic maps of the tecopa 7.5? And amargosa canyon corridor of the dumont dunes 7.5? Quadrangles as PDF and arcgis files. Intended beneficiary(IES) beneficiaries include the amargosa conservancy (which seeks to protect these lands), the BLM (part of the area is designated a wild and scenic river), the scientific community (the region is a natural laboratory for extensional tectonic processes and geomorphology) and general public (people commonly hike through the canyon and appreciate the natural beauty). Subrecipient activities - none