Title: basin evolution across the transition from basin and range extension to transtension in the walker lane belt, nevadaproject period: 02 01 2026-06 30 2027PURPOSE: this project aims to develop…

The U.S. Geological Survey awarded California State University Long Beach Research Foundation a cooperative agreement totaling $174,015.82 on February 1, 2026, under the National Cooperative Geologic Mapping Program (CFDA 15.810), EDMAP component, to develop understanding of extensional basin formation in western Nevada.

Student mentees will generate a new 1:24,000-scale geologic map of the central Stewart Valley, conduct geochemical and geochronological analysis of volcanic rocks, and collect and model gravity data to produce a new gravity map. Geologic mapping will employ high-resolution basemaps and GPS-enabled iPads running the STRABOSPOT geologic mapping software, with field measurements of bedding, fault planes, and slickensides validated against Brunton compass readings. Gravity data collection will use a Scintrex CG-6 AUTOGRAV relative gravimeter and EMLID REACH RS2 multi-band RTK GPS GNSS receivers with centimeter-precision positioning, with surveys conducted along ten east-west profiles in the Soda Springs and Stewart Valleys. Data processing and subsurface modeling will employ Seequent's OASIS MONTAJ software. The work will document timing and rates of faulting and landscape change across fifty million years of plate tectonic evolution and contextualize fossil assemblages in Stewart Valley.

Period of performance runs from February 1, 2026, through June 30, 2027. Place of performance is California.

Title: basin evolution across the transition from basin and range extension to transtension in the walker lane belt, nevadaproject period: 02 01 2026-06 30 2027PURPOSE: this project aims to develop a better understanding of extensional basin formation. The recipient will document the timing and rates of faulting and landscape change in western nevada, a region that has developed from several changes in plate tectonic stresses over the last 50 million years. The focus of this work is to map faults, volcanic rocks, and sedimentary rocks all contributing to the formation of the basin and will also provide context to the unique fossil assemblages preserved and protected in the stewart valley. Activities: to accomplish this project, student mentees will focus on (1) generating a new geologic map, (2) conducting geochemical and geochronological analysis of volcanic rocks, and (3) collecting and modeling gravity data to produce a new gravity map. Geologic mapping will be completed using high-resolution basemaps and imagery together with georeferenced measurements and field observations. Students will perform digital mapping on GPS-enabled ipads using the dedicated geologic mapping software strabospot. Orientations of bedding, fault planes, and slickensides will be measured using the ipad geologic mapping apps, which will be checked against measurements with brunton compasses. Gravity data will be collected by students using a scintrex CG-6 autograv relative gravimeter, with survey point coordinates and heights measured using centimeter-precision emlid reach RS2 multi-band RTK GPS gnss receivers. Data will be collected along a series of 10 east-west profiles in the soda springs and stewart valleys. Data corrections will be performed, and subsurface models will be constructed using seequent s OASIS montaj software. Deliverables and outcomes: the proposed mapping project will result in the creation of a 1:24,000 scale geologic map of the central stewart valley. This area currently only has published maps at scales greater than 1:200,000 or unpublished maps in theses and each of these maps are in disagreement, the new map will rectify discrepancies between the available maps. In addition, the recipient will create a new 1:50,000 gravity map of the stewart valley and soda springs valley. The gravity map will span two valleys and will reveal subsurface faults, and lithology changes that the recipient cannot see with surface mapping. These maps will be made according to USGS gems standards and submitted as high-quality PDF and GIS files to the edmap program officer. Both sets of files will be submitted to the nevada bureau of geology and mining (nbgm) for review as well. The new chemical and geochronology data generated from the project will be reported in the technical reports that accompany the maps and will be made publicly available in perpetuity via online archives. The recipient anticipate two peer-reviewed journal articles to result from this project.intended beneficiary(IES): this work has implications for research communities and government entities who are working to improve resource exploration such as hydrocarbon and mineral occurrences and geothermal energy production, as well as earthquake hazards preparation. The maps will add to databases actively built and maintained by the USGS and nbgm, the gravity data will be added to geophysical databases hosted by the earthscope consortium and the geochronology to the geochronology database (geochron.ORG) for all researchers to access and use.subrecipient activities: project collaborators include DR. K. Loughney at murray state university, who is an expert in the sedimentary units and fossils in the stewart valley, she will help with field work and advise students on unit identification and interpretation. DR. Kevin konrad will train students on laboratory procedures for AR AR geochronology and advise on result interpretation.