At GSA Connects in San Antonio, I had the pleasure of meeting geology graduate student Ryan Parkyn from the University of Nevada-Reno. The AAPG Foundation is helping to fund Ryan’s research into the thermal history of rocks formed in back-arc basins. This week, we’ll travel to the Great Basin of Nevada, a desert landscape of stark beauty, and hear about the secrets held in these fascinating rocks. 🌄
Sharon Lyon
Editor, GeoLifestyle
Jungo Flat, Nevada
Jungo Flat; Courtesy of Ryan Parkyn.
Jungo Flat is located in northwestern Nevada within the Great Basin region, west of Winnemucca. It is accessible via the 100-mile-long Jungo Road, which also connects Burning Man travelers to the Black Rock Desert.
The ghost town of Jungo originated as a Western Pacific Railroad station in 1910. The post office operated 1911–1952. The Haystack Mine, a nearby gold mine, has been actively mining since 1915.
Area geology: Jungo Flat is part of the Basin and Range Province, characterized by alternating mountain ranges and flat valleys formed by fault-block tectonics.
Roughly 50 square miles in area, the Flat is a playa—A dry lakebed, created as ancient Pleistocene lakes evaporated, leaving behind fine silt, clay, and evaporite minerals such as gypsum and halite.
The surrounding hills and ranges include the Jackson Mountains and the Antelope Range.
The Jackson Mountains are composed mainly of volcanic arc rocks, whereas the Antelope Range contain back-arc basin marine rocks.
A regional-scale thrust fault places older volcanic arc rocks on top of the relatively younger back-arc marine rocks.
The area shows signs of ephemeral stream channels and alluvial fan deposits, typical of desert basins.
Aeolian (wind-blown) processes shape surface features, contributing to nearby Winnemucca Sand Dunes, composed primarily of reworked volcanic and sedimentary material.
Ryan’s trip tips: “I camped for about four weeks at Jungo Flat while I was investigating the geology of the adjacent mountain ranges.Camping is legal on most of the playa, as it is public land. It is reachable by high-clearance, two-wheel drive vehicles via a dirt road. I have some very nice photos from here, and the area is known for landscape photography. It is especially scenic in summer light.”
Activities:
Land sailing is common on the Flat due to consistent high winds. Wind-powered vehicles known as “land yachts” reach speeds of 20–50+ miles per hour.
Occasional small aircraft landings have been reported on the Flat.
Look out for space rocks: Because of their light-colored surfaces and minimal vegetation, the playas in this region are known for meteorite finds.
Sponsored
Webinar: An Accelerated Regional Screening Approach for Underexplored Opportunity in the GoA
Join on 3 December 2025 at 12pm CST to learn how to integrate multi-disciplinary geological datasets into a biostratigraphically constrained framework to highlight potential areas for exploration.
Rye Patch State Recreation Area is located in north-central Nevada, along the Humboldt River, west of Winnemucca.
The recreation area is centered around the Rye Patch Reservoir, a 22-mile-long manmade lake with 72 miles of shoreline and 11,000 acres of water surface when full. The Rye Patch Reservoir is formed by the Rye Patch Dam, completed in 1936.
Open year-round, it is popular for recreation and as a base camp for exploring nearby ghost towns, off-road trails, and gold prospecting sites.
Activities: Camping, boating, swimming, and water skiing are major draws at Rye Patch.
Fishing is popular for white bass, catfish, black bass, and walleye.
Hike the trails to observe diverse desert and riparian wildlife. Hawks, eagles, owls, egrets, coots, grebes, cormorants, and Canada geese are common.
Ryan has seen wild mustangs in the surrounding area.
Gold prospecting: The area is also known for placer gold deposits, found downstream from the Rye Patch Dam.
AI/ML tools integrate with our interpretation software and upstream data, supporting consistent, iterative workflows from data preparation through analysis.
An Interview with Ryan Parkyn, University of Nevada, Reno
Ryan in his field area; Deformed strata of the Luning-Fencemaker fold-and-thrust belt, Nevada; Courtesy of Ryan Parkyn.
Q: Ryan, can you describe the geology of your field area for us?
A: “I am studying the Luning-Fencemaker fold-and-thrust belt in central Nevada, about 30 miles northwest of Winnemucca. Here, deep marine sedimentary rocks were deposited in a back-arc basin that developed behind the North American subduction zone in the late Triassic, about 200 million years ago. These rocks, which were deposited below sea level, have been uplifted to an elevation of 5,300 feet. Back-arc basins are sensitive to plate tectonic changes, mantle-generated heat, and tectonic deformation. This leads to the uplift of these basins into mountains via fold-and-thrust belts.”
Q: Your study area is complexly folded, correct?
A: “Yes. By the middle-to-late Jurassic, the back-arc rocks were compressed and thrust over the basinal terrane. Geologic mapping and structural analyses in the Jungo Hills area show greenschist- to amphibolite-grade Triassic rocks that exhibit range-scale overturned isoclinal folding and fold-nappe thrust transport.”
Q: Why are back-arc basins important?
A: “Back-arc basins aren’t just prized for their geologic wonders of transporting low rocks to very high points; they are also highly valued for their ability to generate petroleum. Due to such high temperatures, marine rocks can thermally mature to alter their carbon-bearing organic material into petroleum, the products that humans can refine and use to power our economies. If scientists were better able to understand the details surrounding how back-arc basins heat up, then perhaps we could better understand how petroleum is generated in these settings.”
Q: Can you explain your process?
A: “Understanding how rocks get hot is a first-order control on understanding mountain building. My advisor, Dr. Andrew Zuza, and I collected 200 oriented rock samples, which we are analyzing using a special spectroscopy technique. This method will allow us to determine peak temperatures for the carbon contained within the rocks. These data will help us calculate a geothermal gradient, allowing us to see patterns in the thermal history of these rocks.”
Q: Is there petroleum in your study area?
A: “Little to no hydrocarbons are being extracted from this region of Nevada. This is because these rocks surpassed the temperatures of the thermal maturation window, where temperatures are ideal for petroleum generation. But we can still learn from them and apply our knowledge elsewhere.”
Q: How did support from the AAPG Foundation help your research?
“AAPG Foundation has made a difference in my potential as a student scientist to conduct meaningful geologic research and has allowed me to take my career as a young geoscientist to the next level. By giving me amazing resources to conduct state-of-the-art research that has not been applied to this region before, I’ve had a real chance to learn something new about how back-arc basins tectonically and thermally evolve and to publish my M.S. thesis in a peer-reviewed journal. I’m excited to see what the rocks tell us!”
👍 If you enjoyed this edition of GeoLifestyle, consider supporting AAPG's brand of newsletters by forwarding to a friend or colleague and signing up for our other newsletters here.
➡️ Was this newsletter forwarded to you? Sign up for GeoLifestyle here.
AAPG thanks our advertisers for their support. Sponsorship has no influence on editorial content. If you're interested in supporting AAPG digital products, reach out to Melissa Roberts.
