NEWS RELEASE: Wyoming Geological Survey Summer 2020 Newsletter

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Interpreting the past, providing for the future - summer 2020 newsletter

Earth MRI project focuses on central portion of Laramie Mountains

Laramie Range field work

The U.S. Geological Survey started the Earth Mapping Resources Initiative, otherwise known as Earth MRI, to better understand the national availability and distribution of critical minerals. Critical mineral commodities are non-fuel materials essential to U.S. economic and national security, serve essential functions in manufacturing, and have supply chains that are vulnerable to disruption. In fact, the United States is 100 percent dependent on imports for 21 critical mineral commodities and at least 50 percent dependent on imports for 28 additional commodities. The Earth MRI program utilizes cost-shared cooperative agreements between the U.S. Geological Survey and state surveys to conduct new geologic mapping and collect new geophysical data.

The Wyoming State Geological Survey (WSGS) is participating in the Earth MRI program through a study of the central part of the Laramie Mountains in southeast Wyoming. The emphasis of the project is mapping the King Mountain and Ragged Top Mountain 7.5-minute quadrangles in Albany and Laramie counties. These quadrangles are part of the larger central Laramie Range study area.

The Laramie Range contains known but poorly understood rare earth element-enriched alkalic plutons, two anorthosite complexes, a greenstone belt, and a large mafic dike swarm. The anorthosite complexes cumulatively have potential for base- and precious-metal deposits (Cu, Ni, Au, Ag) as well as critical mineral resources (Ti, V, W, Cr, and REEs). Metavolcanic rocks of the Elmers Rock Greenstone Belt are a potential source of Ni, Cr, and Mo. Additionally, several known occurrences of graphite fall within the focus area, including the Rabbit Creek graphitic schist deposit in Platte County near the northernmost part of the study area.

This two-year project will focus primarily on geologic mapping and geochemical analyses, cumulating in the publication of two maps and a geodatabase of geochemical results.

This is also a collaborative project with several members of the University of Wyoming’s Department of Geology and Geophysics: Dr. Ron Frost, emeritus professor, who mapped much of the Laramie Range over the past several decades; Dr. Simone Runyon, assistant professor and economic geologist; and Janet Dewey, associate research scientist and analytical geochemist.

Amato joins GIS department at the Survey

James Amato

The WSGS welcomed a new staff member to the team this summer. James Amato is the agency’s new geospatial technical principal and map editor. He replaces Suzanne Luhr, who retired from the position in May.

Amato is a Wisconsin native and received his bachelor’s and master’s degrees in geology from the University of Wisconsin-Milwaukee with an emphasis in sedimentology, glacial geomorphology, and geophysics. At the WSGS, he serves as the agency’s primary point of contact for geospatial data and technologies. He also provides end-user support in project development, analysis, and outreach, and edits geological maps and databases for accuracy, aesthetics, and standards.

“I look forward to having the opportunity to study the geology of Wyoming and how it applies to the state’s mineral and energy resources, in addition to bringing public awareness to the state’s geologic hazards through data and visualization,” Amato says.

Hiking is what drew Amato to a career in geology. While pursuing his degree, he stumbled upon the application of GIS, which eventually led him to complete a professional certificate during his graduate studies.

“The idea of assimilating the natural world using geospatial technology intrigues me,” he says.

Prior to coming on board at the WSGS, Amato worked for the geology department at the University of Wisconsin-Oshkosh as an instrumentation specialist. He also co-instructed the school’s geology field camp in Utah and co-led other interim field courses to Hawaii, Bermuda, and the Black Hills.

Internships with the U.S. Geological Survey in 2016 and Wisconsin Geological and Natural History Survey in 2017 sparked his interest in working for a state or federal agency.

“I wanted to work at an agency where I could implement my technical skills of GIS in conjunction with my passion for geosciences,” he explains.

Why Wyoming?

“It has everything that excites a geologist,” Amato says. “It has always been one of a handful of states in the West that has captured my attention because of its unique landscapes and vastness.”

First on the list of places to explore is the Snowy Range and Laramie’s other surrounding areas.

“I love alpine hiking and am very excited to have the Medicine Bow Mountains in my backyard,” he says. “I can’t wait to get back to the Tetons and also the Flaming Gorge area.”

Statewide groundwater salinity report now available

Groundwater quality varies greatly throughout Wyoming’s basins, which serve as home to most of the state’s population and economic activity. One measurement of water quality is salinity—the amount of dissolved material that remains as residue after the liquid portion of a water sample evaporates.

The WSGS investigated groundwater salinity at a statewide level and found that naturally occurring groundwater salinity varies widely within individual geologic formations, at different depths, and throughout the state. The results from the study can be found in Open File Report 2020-6, Groundwater Salinity in Wyoming.

The project examined thousands of water quality analyses from the U.S. Geological Survey and Wyoming Oil and Gas Conservation Commission. The publication includes an explanation of groundwater salinity and maps of water quality by salinity level throughout Wyoming.

The report is the latest in an ongoing series about salinity in Wyoming. Previous reports examined the salinity of groundwater in the Powder River Basin and Denver-Julesburg Basin. Geoscientists are currently working on a report about groundwater salinity in the Greater Green River Basin scheduled to be released this year.

STATEMAP program produces 5 maps


The WSGS released five geologic maps of western Wyoming this spring.

Geologists mapped the Earnest Butte, Lion Bluffs, and South Baxter quadrangles, all on the southern end of the Rock Springs Uplift in Sweetwater County. The new maps provide key information on the timing of deformation of the uplift and insights into the mineralization history of the entire region.

The projects incorporated a range of analytical data collected from the study areas, including new detrital-zircon geochronology, geochemistry of whole rock and stream-sediment samples, and palynological as well as source-rock analyses.

All three maps will contribute to the Firehole Canyon 1:100,000-scale bedrock geology map the WSGS is working toward completing.

The Lincoln County (Blind Bull Creek and Pickle Pass quadrangles) projects focused on mapping of the Greys River fault extent. Geologists also investigated and mapped landslides in the area.

Other outcomes of the work included the mapping of previously undifferentiated Pinedale and Bull Lake glacial deposits and fluvial terraces along the Greys River.

The mapping projects are part of the STATEMAP program, which is a cooperative agreement with the U.S. Geological Survey’s National Cooperative Geologic Mapping Program.

Geologists are currently in the field gathering data for the next set of STATEMAP projects, which will be published in 2021. Quadrangles being mapped are: Richards Gap in Sweetwater County, Jackson Lake in Teton County, Goat Mountain in Albany and Laramie counties, and Rock River in Albany, Laramie, and Platte counties.

Learn about Yellowstone’s geology with new interactive map

Yellowstone National Park is perhaps the most famous attraction in Wyoming. The world’s first national park, Yellowstone offers distinctive geology that can’t be found anywhere else.

The WSGS developed a new interactive map that offers an opportunity to learn about the park’s geology. Since its launching in May, there have been more than 7,700 views of the Geology of Yellowstone Map. Scientists have found the new platform valuable in that it offers a single interface to view multiple geologic maps and datasets. General public users have expressed excitement about live data, such as webcams.

“We’re pleased with the early feedback we’ve received on the map,” says WSGS geologist James Mauch. “Our goal was to compile the wealth of geospatial data that’s been published on Yellowstone into a single interactive map that can be used by both researchers and the general public. We hope that it becomes a go-to resource for digital exploration of Yellowstone’s geology, and we look forward to incorporating additional data in future updates to the map.”

The online map is a compilation of publicly available geospatial data from the Yellowstone Volcano Observatory (YVO) partners and external sources. The WSGS is a consortium member of the YVO, which is composed of state and federal agencies and universities that provide timely monitoring and hazard assessment, contribute scientific understanding, and disseminate information to the public on the Yellowstone volcanic system.

Map features

Users can interactively pan and zoom to areas of interest on the map, search for specific locations, and turn layers on and off. Clicking on a feature leads to a pop-up window with more information, which can also be accessed in each layer’s attribute table. Key features of the map are the Layer Explanation and Data Sources menus, which provide users with links to the original data source for each layer.

The map includes several layers of bedrock and surficial geologic maps published by the U.S. Geological Survey and National Park Service. Users will also find layers containing information on Yellowstone’s geology, thermal features, hydrography, active monitoring programs, geomorphology and geologic hazards, and basic geography.

The WSGS plans to make periodic updates and additions to the map as new studies are published, and new information is collected through data monitoring. Mauch says he is planning for the next update to occur in the fall.

Data from reanalysis of archived stream-sediment samples released

A new WSGS Open File Report published this summer is a release of geochemical data from a reanalysis of archived stream-sediment samples originally collected under a 1970s federal uranium exploration program. The new data will help to establish modern baseline geochemistry for future studies of mineral systems and deposits across Wyoming.

The uninterpreted “raw” data are available as received from the laboratory, providing geologists and the mineral industry with the opportunity to use the data for research and exploration purposes.

The geochemical results are provided as Excel spreadsheets that accompany a short report detailing the sampling methodology, available as a free download from the WSGS website.

Learn more about the project in the news release.

Retired WSGS geologist celebrated

The Rocky Mountain Federation of Mineralogical Societies and Wyoming State Gem & Mineral Society presented an honorary award to retired WSGS geologist Wayne Sutherland during the annual Wyoming Gem & Mineral Show in June in Marbleton. The plaque honors Wayne for his “distinguished achievement in the field of earth sciences.”

At the time of his December 2019 retirement, Wayne held the gemstones, metals, and economic geologist position at the WSGS. His career as a geologist spanned more than 40 years for both private companies and government agencies.


A few favorite superimposed rivers

As we enjoy the brief, glorious Wyoming summer, I’d like to highlight a few places where we can admire spectacular geology and enjoy a cool river. But not just any type of river—superimposed rivers are unique because they flow through resistant bedrock and can be found in places where rivers are not expected to flow.

Superimposed rivers initially cut down through soft, easily erodible layers (generally flat-lying Eocene and Oligocene beds in Wyoming). Eventually, the paths of these rivers became spatially constrained, and they continued to carve into the underlying, more-resistant rocks. 

A few of my favorites include Ayers Natural Bridge near Douglas, where La Prele Creek has cut 800 feet into the Pennsylvanian Casper Formation. In addition to the steep-walled canyon, visitors can explore the natural arch, which formed when the creek cut off a large meander loop by eroding through the base of a cliff at the cut bank.

Devils Gate is a 330-foot canyon formed where the Sweetwater River flows through a ridge of Archean granite near Independence Rock in central Wyoming. The chasm is 400 feet wide at the top and just 30 feet wide at the bottom.

North of Lovell, the Bighorn River cut through Paleozoic rocks to form walls more than 2,000 feet high. The canyon offers scenic exposure of geologic units ranging from the Cambrian Gros Ventre Formation to the Mississippian Madison Limestone, which comprise the majority of the cliffs.

Just west of Cody, the Shoshone River cuts through Paleozoic and Archean rocks to form Shoshone Canyon. On either side of the canyon, Rattlesnake Mountain and Cedar Mountain are mirrored halves of the same faulted anticline, bisected by the river. 

An extensive stratigraphic section is exposed in Wind River Canyon south of Thermopolis. Here the Wind River has eroded through resistant rocks ranging in age from Mesozoic to Archean to form steep walls as high as 2,500 feet. The stunning cliffs can be followed for miles and are formed primarily by the Ordocivian Bighorn Dolomite, Mississipian Madison Limestone, and Pennsylvanian Tensleep Sandstone.

These creeks and rivers continue to erode into the basement rocks that form their beds, and these canyons will continue to deepen and expose older and older rocks over the next few millions of years, giving us plenty of time to enjoy the river paths and geologic exposures as we see them today.

--Dr. Erin Campbell, Wyoming State Geologist and WSGS Director

State park geology

State parks showcase some of the geology unique to Wyoming, and summer is a great time to visit the various parks scattered across the state.

The WSGS in the last few years has published information pamphlets detailing the geology found in individual parks. Pamphlets are free and are available at park visitor centers, at the WSGS office in Laramie, and as free downloads from the agency’s website.

Here’s a glimpse of what you’ll find in each pamphlet:

Curt Gowdy—Learn how the Laramie Mountains came to be and about the Sherman batholith, a large mass of igneous rock that crystallized from magma deep within the earth more than a billion years ago. Different granites in the Sherman batholith are explained, as is the geologic feature, the “Gangplank.”

Seminoe—The geology exposed at this park ranges in age from 2.7 billion years to active sand dunes. There are red rocks, or “red beds,” in the park, as well as a formation that contains dinosaur tracks and marine fossils.

Bear River—This park is part of a landscape shaped by ancient mountain-building processes and multiple episodes of faulting. The pamphlet explains how an inland lake millions of years ago once occupied the area.

Glendo—Geology exposed at Glendo represents more than 300 million years of Earth history and is largely visible because the North Platte River cut a canyon through the region, leaving the landscape seen today.

GuernseyGuernsey has a mining history worth knowing. The pamphlet describes how Native Americans mined hematite and other minerals. There’s also a section about the most prominent rocks within the park.

Keyhole—This park is in the Black Hills region and offers geologic formations in a range of ages. Learn how the area’s rocks tell the story of a large inland seaway that once covered much of the state.

Buffalo Bill—The Great Unconformity, a dormant volcanic field, and the world’s largest known ancient landslide are some of the unique geologic features found in this park

Edness K. Wilkins—This park is favorably located for viewing geologic landforms in the area, including Casper Mountain, alluvial fans, and a large, active sand dune field. 

All pamphlets include a hydrogeology section and a bedrock geologic map. Geologists are working on wrapping up the series with pamphlets about Hot Springs, Boysen, and Sinks Canyon state parks.

Bird fossil projects in the works

The WSGS and Wyoming State Museum have contracted fossil preparator Michael J. Eklund to prepare a whole bird fossil discovered by Rick Hebdon of Warfield Fossil Quarries in the Green River Formation in western Wyoming. The bird, tentatively identified by paleontologist Dr. Daniel J. Field (Department of Earth Sciences, Cambridge University) as a Primobucco, will be included as part of the Wyoming State Museum's long-term earth sciences display. Plans for partial preparation of the specimen in front of a live audience at the museum have been delayed due to the COVID-19 crisis.

Two other bird fossils, also from the Green River Formation near Kemmerer, are also in preparation by Eklund. These fossils were found by Ulrich's Fossil Gallery. The specimens have been preliminarily identified by Field as a Lithornithid and a Stem Passerine. These specimens are slated to be studied in detail and described by Field.