USGS invests Bipartisan Infrastructure Law funding to map critical mineral potential along South Dakota, Iowa, and Minnesota borders

The data collection will be conducted through the USGS Earth Mapping Resources Initiative (Earth MRI), a partnership between the USGS and state geological surveys that is revolutionizing our understanding of the nation's geology and critical mineral resources, which are vital to the U.S. economy, national security, and energy technologies.

"We lack the high-quality data we need to understand our nation's geologic resources, but Earth MRI is changing that by transforming and modernizing our nation's mapping," said David Applegate, USGS director.

Earth MRI has collected an unprecedented volume of foundational data across the nation and accelerated mapping in areas with potential for hosting critical mineral resources, such as the greater Sioux Falls, South Dakota region and the borderlands of Minnesota and Iowa.

"This airborne survey will help us gain a much better understanding of the Precambrian geology in the region, which is entirely concealed by younger rocks and sediments, and advance our knowledge of potential resources as well as the geologic context that creates them," said Ben Drenth, lead USGS geophysicist for this survey.

The rocks in this specific region are believed to contain nickel, chromium, and cobalt, all typically used to create stainless steel and rechargeable batteries, as well as platinum-group elements. These elements, called PGEs, tend to occur together in nature, and are indispensable to many industrial applications.

The survey footprint was designed in collaboration with the state geological surveys to best capture much needed data in the area and leverage state-level expertise to inform decision makers and land managers.

"The radiometric data collected in this survey will offer us a completely new dataset that we've never had before and will greatly benefit our geochemical mapping program," said Ryan Clark, a geologist with the Iowa State Geological Survey.

Earth MRI data support long-term strategies and planning for strengthening mineral supply chains, while also expanding the possibility for new research and strengthening the geoscience workforce.

"I'm optimistic about what this data will mean for future generations of geoscientists," said Darren Johnson, a geologist with the South Dakota State Geological Survey. "I'm excited to see the different ways in which this data is used over the next 20 to 30 years, not just in terms of mineral exploration but other areas of scientific research and how our understanding of this area's geology will change."

These airborne geophysical surveys will collect a combination of magnetic and radiometric data. These data can be used to map rocks from just beneath trees, grass, and shallow sediment cover down to several miles underground. Magnetic data can be used to identify ancient faults, different rock types, and other geologic features, as well as potentially the signatures of mineral deposits, while radiometric data indicate the relative amounts of potassium, uranium and thorium in shallow rocks and soil.

Combined, these data provide major insight into the geologic framework of the nation and support state and local governments in planning their economic futures and managing natural resources.

Scientists use this information to help map rocks that may contain mineral deposits, faults that may rupture during an earthquake, areas that may be prone to increased radon, and areas likely to contain groundwater or energy resources.

The initial airborne geophysical survey may be followed by additional investments, including new geologic maps, geochemical sampling, and other techniques to better understand the region's geologic framework and mineral potential.

Since 2021, the Bipartisan Infrastructure Law has advanced scientific innovation through a \$320 million investment for the USGS to better map the Nation's mineral resources, both still in the ground and in mine wastes, and to preserve historical geologic data and samples. Through the end of fiscal year 2024, more than \$160 million has been obligated for Earth MRI initiatives, propelling efforts to make "once-in-a-generation" advancements in the nation's geologic and geophysical data collections and mapping.