My current research focus is on uranium within the White River Group. I am also interested in kimberlites, particularly from the state-line district of Wyoming and Colorado, as well as mining geology in general. Below is my current proposal for my Master’s thesis. I will be working on this project with my advisor Dr. Susan Swapp.
The White River Group as a Potential Uranium Resource
Introduction
Uranium is a vital resource to America’s economy and security. It is used not only for nuclear power generation, but also has many applications within the medical, industrial, and military fields as well. Finding and developing uranium resources within our own country’s borders is therefore imperative to our future. Uranium production in the United States had been in decline for decades and almost became nonexistent in the early 2000’s with only three operating mines (Energy Information Administration, domestic energy report). Thanks to the uptick in uranium ore prices production had increased since then, but again is now declining. The use of in-situ mining to produce uranium ore has also helped to lower costs and has made low grade ore deposits now viable.
The White River Group is a collection of sedimentary deposits and ashfalls covering a vast area from northern Colorado to North Dakota. The ash deposited within this group contains uranium (Moore and Levish, 1955), which could potentially be a source for the roll front deposits in the region. The other possible uranium sources are the Archean and Precambrian crystalline rocks located in Laramide uplifts. These potential uranium sources need to be identified and whether they are responsible for the uranium roll fronts found in the adjacent basins.
By analyzing core samples from the White River Group it will be possible to identify whether the uranium comes from the tuffs within it or if it comes from the Laramide uplifts. Thorium is immobile when subjected to weathering, unlike uranium. Uranium will leach out into solution (U4+ to U6+) and can be transported until it gets reduced again (U6+ to U4+). This process is responsible for the creation of roll front deposits. By measuring the ratios of Th/U throughout the White River Group it will be possible to determine the source for the uranium (Sibray, 2011). The source will have higher Th/U ratios versus the other units and will thus identify it as a source.
Research Questions
1. Are the tuffs within the White River Group the uranium sources?
2. Are there units within the White River Group where the uranium gets concentrated into roll front deposits?
3. How did the uranium get transported to the roll fronts and are they still active systems?
Figure 1: Idealized cross section of a sandstone hosted
uranium roll front deposit. (Cyclone
Uranium Corporation, 2012)
Methods
I will analyze multiple cores from the White River Group in the Core Teaching and Research Lab at the University of Wyoming. The lab currently has six cores from the White River Group in its possession. The cores will be examined and measured to determine and classify the different rock units within it. Once this is done, samples will be taken from the different sections at predetermined intervals. These samples will be characterized by their mineralogy, petrography, and whole rock chemical compositions.
Samples containing uranium will then be studied at Stanford using the sensitive high resolution ion microprobe (SHRIMP) to date the uranium bearing zircon crystals. This will allow for dating of the various rock units, which will help constrain the emplacement and development history of the White River Group. Further analyses on the uranium bearing samples will be undertaken in the Wyoming High Precision Isotope Laboratory to measure the uranium and thorium isotopic ratios. These ratios will then be used to determine the source units within the White River Group. Field relations can then be constrained to show if there is any vertical variation within the source unit.
Anticipated Results
1. The uranium sources will be identified within the White River Group.
2. Sites for roll front deposits in the White River Group will be constrained.
3. The processes of uranium transport and deposition will be identified and whether the system is still active or not will also be determined.
Intellectual Merit
The White River Group has yet to be studied in any great detail and the uranium sources for the roll front deposits in the region have also not been identified. Radiometric dating places their deposition during the Oligocene (Moore and Levish, 1955), but the volcanic source responsible for the tuffaceous deposits within the group has not been constrained. This research will help characterize these deposits and provide further insight into their depositional history.
Broader Impacts
This research will characterize the White River Group and also determine its uranium potential. The White River Group has not been studied in any great detail and this research will help add to this gap of knowledge during the Oligocene. Determining the uranium sources will also allow for greater exploration possibilities. This will allow for increased production of uranium ore and a move towards cleaner energy in America, as well as a move towards greater energy independence. Understanding how uranium roll front deposits develop will increase our ability to locate new ones. With the development of in-situ mining techniques these low grade ore deposits represent a new wave of uranium exploration and production possibilities.
Budget
The budget below totals $31,840 and includes all costs associated with retrieving, analyzing, and compensating those involved with the project. The timeframe for the project will be under two years to complete.
Bibliography
Cyclone Uranium Corporation, (2012). Idealized cross-section of a sandstone-hosted roll front uranium deposit. http://www.cycloneuranium.com/project-wyoming.php
Energy Information Administration, Domestic Uranium Production Report (2014). http://www.eia.gov/uranium/production/annual/
Moore, George W. and Levish, Murray (1955). “Uranium-Bearing Sandstone In The White River Badlands Pennington County, South Dakota.” Geological Survey Circular 359.
Sibray, Steven (2011). “Potential Uranium Source Rocks of the White River Group in Western Nebraska and South Dakota” Search and Discovery Article #80186.