WoldWide Drilling Resource

Iowa’s Hidden Potential May Be Its Geology Adapted from Information by The University of Iowa University of Iowa (UI) geologists are leading an effort to determine the age of an underground formation encompassing a ten-county region in northeast Iowa. They are hoping to determine if it is similar to a geologic complex beneath Duluth, Minnesota, which has minerals valued as high as $1 trillion. If the Northeast Iowa Formation is found to be roughly the same age as the Duluth Complex, it could mean the Iowa region contains similar economically valuable deposits, such as copper, nickel, platinum, and other metals, but a final determination won’t be made until a second core is drilled in the region. These minerals matter because they are used for industrial, medical, technological, and energy-generation purposes. Platinum is used in catalytic converters for vehicles and may have a potential use in hydrogen fuel cells. Lithium is used in batteries which power a host of electronic devices. Global demand for such minerals is increasing, straining existing known supplies. The U.S. Geological Survey’s (USGS) Mineral Resources Program has started preparing a new national assessment of mineral resources. An area of particular interest is the Midcontinent Rift System, a formation more than one billion years old extending from Kansas to Michigan. Within this stretch, the USGS is interested in the northeast Iowa region. In 2012, they conducted the first airborne survey of the terrain around Decorah, which yielded a more detailed picture of the underlying geology, including the identification of the horseshoe-shaped Decorah Complex. They conducted a second survey over a larger area which included Elkader, Manchester, and Vinton. This survey also showed geologic features such as rings and horseshoe shapes. Neither survey dated the Northeast Iowa Formation, which meant both were unable to verify whether it’s related to the Duluth Complex. Since August 2018, Allison Kusick, a UI junior and geology major, has spent each Tuesday at the Iowa Geological Survey’s warehouse at the UI’s Oakdale Research Park to study a core drilled near Elkader by a mineral prospecting company in the 1960s. Under the direction of Earth and Environmental Sciences Department Professor David Peate, Kusick takes a segment of the nearly half-mile-long core and aims a series of beams from a portable X-ray fluorescence analyzer at it. The instrument almost instantaneously produces a summary of the type and concentration of minerals in the area of the core illuminated by the X-ray. In a section of the core obtained around 2410 feet belowground, Kusick found the mineral compound zirconium, which general ly contains a mineral called baddeleyite. This mineral can be used to date the rocks by calculating the decay of uranium trapped inside. Kusick and Peate took the sample to the UI’s Electron Microprobe Laboratory, where a more in-depth analysis of the crystals produced another surprise - the pres- ence of the mineral zirconolite. The zir- conolite also provided a precise method of dating, meaning UI geologists had two reliable age-dating candidates for the core. Samples will be sent to a USGS facility in Colorado for dating. “I think it’s cool,” said Kusick. “I’m learning a lot more, not just about ele- ments and minerals, but I’m learning about the instruments that geologists use every day. And, there could be an economic piece to this as well.” If the core drilled near Elkader is shown to be of the same age as the Duluth Complex, geologists would like to seek funding to drill a second core in the Northeast Iowa Formation. Allison Kusic holds a piece of the core sample. ENV 30 JULY 2019 WorldWide Drilling Resource ®