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Item A thermochronological history of burial and exhumation at Kevin Dome, Northwest Montana including the origin of CO2 in Upper Devonian Duperow Formation and the Bakken Petroleum system at the Dome(Montana State University - Bozeman, College of Letters & Science, 2022) Adeniyi, Elijah Olusola; Chairperson, Graduate Committee: Mary S. Hubbard; This is a manuscript style paper that includes co-authored chapters.Kevin Dome is a geologic structure and historic hydrocarbon producer in northwest Montana. This structure is also a known CO 2 reservoir, yet its development has not been constrained with thermochronological techniques and the origin of the natural (~ 283 x 109 m 3) CO 2, of the Upper Devonian Duperow Formation, is not well understood. This work seeks to create a temporal understanding of the burial and exhumation history of Kevin Dome including the hydrocarbon generation and CO 2 emplacement. I constrained the burial and exhumation history at Kevin Dome with low-temperature thermochronology, carbonate clumped isotope thermometry, and thermobarometric proxies. I also tested for microbial, thermogenic, and magmatic CO 2 source(s) as well as CH 4 and N 2 gas sources at the dome with major gas composition, stable and noble gas isotopic geochemistry methods. I found that Kevin Dome rocks were buried to oil and gas generation windows before exhumation during the Late Cretaceous-Paleocene (~65 - 72Ma) and the Oligocene-Miocene (~ 15 - 26Ma) at an average rate of ~ 0.27 mm/yr. My study supports an evolved forebulge-dome origination model for Kevin Dome that is driven by the Late Cretaceous-Paleocene emplacement of the Rocky Mountain overthrust in a Foreland Basin setting in northwestern Montana (and proximal Canada) and an Oligocene-Miocene erosional or epeirogenic event not previously recognized in northwest Montana. I estimated ~4 - 5 km more overburden erosion than was previously thought in the region and suggest that the Oligocene-Miocene exhumation terminated hydrocarbon generation at Kevin Dome. In terms of CO 2 origin, my data supports a magmatic origin for the Duperow CO 2, with emplacement during the Sweetgrass Hills igneous complex intrusion(~52 Ma). I also found that the CH4 and N2 gases at Kevin Dome were mainly thermogenic in origin. A CO 2 solubility model showed that ~98% of the CO 2 has been dissolved into the groundwater in the Bakken petroleum system's hydrocarbon-bearing reservoirs at Kevin Dome during migration. I present a novel approach of integrating modern t-T sensitive techniques, stratigraphy, thermal maturity data, and isotopic geochemistry to address the structural development of sedimentary basins/domes, hydrocarbon generation, and magmatic CO 2 emplacement and subsequent evolution.Item An investigation of the reactions of supercritical CO 2 and brine with the Berea sandstone, muscovite, and iron bearing minerals(Montana State University - Bozeman, College of Letters & Science, 2015) Mangini, Seth Alexander; Chairperson, Graduate Committee: Mark L. SkidmoreThe reduction of anthropogenic CO 2 emissions while still generating energy is a challenge that society faces. Most current energy production comes from fossil fuels that increase atmospheric CO 2 concentrations. Pending a breakthrough in clean energy production, technological solutions that increase efficiency and sequester CO 2 are required. Carbon Capture and Storage (CCS) or carbon sequestration technology can provide part of the solution by providing disposal of point source CO 2 emissions. The research described in this thesis aims to aid development of CCS technology. There are three parts to the thesis. First, is an experimental study of the Berea sandstone to determine the reactivity of its minerals, as these could impact its potential as a reservoir for CO 2 storage. Cores of Berea were placed in a "flow-through reactor" that pumped a continuous stream of supercritical CO 2 (scCO 2) mixed with simulated groundwater through the rock. Chemical and physical changes to the solid, liquid and gas phases were monitored. Second, batch experiments were conducted to study the behavior of pyrite, magnetite, hematite, and muscovite when subjected to simulated groundwater and scCO 2. Third, is an outcrop study of the Devonian Jefferson Formation, a carbonate formation to serve as an analog to the same formation in the subsurface where it is the target of a Department of Energy CCS pilot project. The field study provided analysis of the mineralogy, sedimentology, and stratigraphy so as to better understand its potential as a reservoir for CO 2 storage. The flow-through experiments on the Berea sandstone demonstrated that carbonate cement and iron oxides were reactive phases. It was equivocal as to whether muscovite was reactive. The batch experiments quantified the reactivity of iron oxides and pyrite and demonstrated significant dissolution of the scCO 2, such that supercritical conditions were not maintained for the duration of the experiment. The batch experiments also showed that muscovite was not reactive within the time frame of the Berea flow-through experiments (72 hours), but was reactive over longer time periods (500+ hours). The field study indicated that the best potential reservoir zones of the Jefferson Formation are altered reef complexes composed mostly of dolomite.Item Structurally-controlled hydrothermal diagenesis of Mississippian reservoir rocks exposed in the Big Snowy Arch, central Montana(Montana State University - Bozeman, College of Letters & Science, 2014) Jeffrey, Sarah Rae; Chairperson, Graduate Committee: David R. LagesonThe subsurface characterization of three-dimensional structural traps is becoming increasingly important with the advent of new technologies for the sequestration of anthropogenic carbon dioxide, which often takes place within preexisting, sealed reservoirs to permanently store greenhouse gasses that are detrimental to the global climate. Within the Big Snowy Arch, central Montana, reservoir units that are targets for carbon sequestration have experienced Laramide and younger deformation and widespread Eocene igneous activity, which introduced a heating mechanism for hydrothermal fluid flow and created anisotropy in Mississippian strata. One particular region of interest is the western flank of the Big Snowy Mountains, which contains a northeast-southwest striking, high-angle fault zone which has acted as a conduit for hydrothermal brine solutions into the overlying Phanerozoic rocks. Such fault zones often branch and bifurcate as they propagate up-section through the overburden, until a loss of thermally-driven hydrodynamic pressure terminates the upward movement of carbon dioxide-rich brines, leaving a distinct assemblage of collapse breccia rich in hydrothermal minerals, such as saddle dolomite and sulfide precipitates. To determine the degree of structurally-induced anisotropy within the reservoir units, field techniques (detailed structural measurements and lithologic descriptions) coupled with analytical methods (X-ray diffraction spectrometry, stable carbon and oxygen isotope analyses, secondary electron imagery, and petrography) were utilized. These techniques presented concrete evidence of hydrothermal mineralization and episodic fluid flow within the brecciated region of the fault zone. These areas are major avenues of enhanced porosity and permeability in the subsurface, which has important applications at some sites in Montana where carbon sequestration is under consideration (e.g., Kevin Dome).