Earth Sciences Commons^™

Investigation Of The Sheep Creek Carbonatites, Ravalli County, Montana, Sarah Risedorf

Graduate Theses & Non-Theses

Carbonatite-related REE-Nb mineralization in southern Ravalli County, Montana was first discovered in the late 1950s and early 1960s. Over 30 discontinuous carbonatite bodies occur in a ~ 10 km² area centered on Sheep Creek, a tributary to the headwaters of the West Fork of the Bitterroot River (WFBR). The deposits are contained in a belt that extends to the southeast into the Mineral Hill district of Lemhi County, Idaho. Country rocks include a deformed and metamorphosed bimodal igneous suite of diabase and A-type granite, both dated to 1.37 Ga by previous workers. These rocks are locally metamorphosed to amphibolite …

Limitations To Photosynthesis In Silver Bow And Blacktail Creeks, Isaiah Robertson

Graduate Theses & Non-Theses

Throughout Silver Bow Creek’s history, consideration of the photosynthetic communities that make heterotrophic life possible have often been overlooked since macroinvertebrates made up a majority of ecosystem health assessments. Silver Bow Creek has had minimal biological research outside of macroinvertebrate surveys, especially as it pertains to photosynthetic organisms. This study assessed the photosynthetic communities of Silver Bow Creek and their limitations by limiting available light and comparing uptake of nutrients during a 23-day incubation experiment conducted at four sites along the flow of Silver Bow Creek and Blacktail Creek. At each site, nine one-liter microcosms, filled with creek water and …

Hydrothermal Water-Rock Reaction Modeling With Microbial Considerations: Rabbit Creek Area, Yellowstone National Park, Wy, Shanna Law

Graduate Theses & Non-Theses

Water-rock reactions at depth are the main control on aqueous hydrothermal chemistries of hot springs and other thermal features. Thermophilic microbes living in the hydrothermal system are a secondary control on aqueous hydrothermal chemistries and are expected to have increasing influence as spring temperatures decrease. The Rabbit Creek area of Yellowstone National Park (YNP) is an ideal case study for investigating the geologic and biologic controls on aqueous hydrothermal chemistries due to the proximity of the drill core Y-5 to geochemically diverse hydrothermal features (17.3⁰C to 92.2⁰C ± 0.1⁰C; field pH values 6.50 to 9.60 ± 0.05).

The modeling program …

Tracking Potential Leakage Of Tailings-Lake Water Into Background Groundwater In Butte, Montana, Using Geochemical And Stable Isotope Tracers, Matthew Berzel

Graduate Theses & Non-Theses

This study was conducted to identify environmental tracers using water chemistry and stable isotopes in the Moulton Road area adjacent to the Yankee Doodle tailings impoundment north of Butte, Montana. The water level of the tailings lake is being raised as tailings slurry is pumped up to the impoundment, and numerous residential wells are located in close proximity. Although it has an alkaline pH (> 9), the water in the tailings lake is much higher in some chemical constituents than the wells and some of these constituents could be used as tracers to determine if lake water is migrating out …

Foundations For A Geobiochemical Characterization Of Mudpots In Yellowstone National Park, Georgia Dahlquist

Graduate Theses & Non-Theses

Mudpots are acidic, turbid thermal features formed by the argillic or sericitic alteration of rock with enough fluid to create a viscous feature. Prior to this research, the combination of interdisciplinary sampling for geochemistry, mineralogy, and microbiology of rhyolite hosted mudpots, particularly in chemically distinct subregions of an area, remained largely unavailable. This work discusses mudpots and nearby hot springs sampled in Yellowstone National Park (YNP) in July 2016 and the measured in situ pH, temperature, and conductivity values, and dissolved oxygen concentrations. Water, filtered via gravity pre-filtration and 1.2 μm and 0.8/0.2μm syringe filtration, yielded δD and δ18O values …

Biogeochemical Interactions In Flooded Underground Mines, Renee Schmidt

Graduate Theses & Non-Theses

This study presents a biogeochemical analysis of microbial communities in flooded underground mines in Butte, Montana, USA. Samples were collected from nine mineshafts representing three distinct geochemical zones. These zones consist of the East, West, and Outer Camp mines. The East Camp mines, bordering the Berkeley Pit Superfund site, have the highest concentrations of dissolved metals and the most acidic pH values. Dissolved metal concentrations in the West Camp are one to three orders of magnitude lower than in the East Camp and have nearly neutral pH values. The Outer Camp mines have similar metal concentrations to the West Camp …

Mineralogy And Geochemistry Of The Heddleston Porphyry Cu-Mo Deposit, Montana, Ben Schubert

Graduate Theses & Non-Theses

The Heddleston porphyry Cu-Mo deposit is located in Lewis and Clark County, Montana, near the headwaters of the Blackfoot River. It is immediately west of the historic Mike Horse mine, an important producer of Pb-Zn from polymetallic veins and lodes. The Heddleston property was explored extensively by the Anaconda Company in the 1960s and 1970s, but was never mined. Specimens of polished drill core from the deposit are archived in the Anaconda Research Collection at Montana Tech campus. The purpose of this research project was to use the archived samples to examine the geochemistry and mineralogy of the Heddleston and …

Supergene Mineralization Of The Continental Pit, Butte, Silver Bow County, Montana, Kyle Eastman

Graduate Theses & Non-Theses

The Butte porphyry Cu-Mo-Ag deposit has been considerably altered by supergene processes that enriched Cu and Ag, and mobilized other metals. Supergene enrichment provided early miners with excellent ore grades, and contributes significantly to current mining operations in Butte. The Continental Pit exhibits the classic leached and enriched vertical zonation that is common in near-surface porphyry systems around the world. Although studied by the Anaconda Copper Mining Company during the mid-20th century, significant and economically relevant questions remain regarding this deposit’s supergene heavy metal geochemistry and its relationship to the local hydrology and tectonic history.

This thesis investigates the paragenesis …

Anaerobic Dissociation Of Thiocyanate Under Controlled Ph And Temperature, Alero Gure

Graduate Theses & Non-Theses

Thiocyanate (SCN-) is formed from both natural and industrial processes, including the use of cyanide to process gold and silver ores rich in sulfide minerals. In mining operations however, thiocyanate also plays a role as an alternative lixiviant to cyanide for leaching gold and silver out of their ores. Thiocyanate may be less toxic than cyanide but it is more stable and has proven to be more difficult to destroy in mining effluents. In addition, just like cyanide, an environmental contaminant of concern – nitrate – is the final product of the oxidation of thiocyanate.

This study investigated the chemical …

Natural Acid Rock Drainage And Ferricrete Deposit Chemistry Of The Judith Mountains, Montana, Sara Edinberg

Graduate Theses & Non-Theses

The Judith Mountains are a low-elevation “island” mountain range in east-central Montana composed of a series of laccoliths and stocks cut by coarse-grained alkali granite and tinguaite dikes. The geology of the Judith Mountains in the vicinity of Red Mountain and Judith Peak, two of the tallest mountains in the range, is conducive to the creation of headwater streams that are naturally acidic. Extensive limonite staining on Red Mountain attests to the widespread presence of disseminated pyrite in hydrothermally altered porphyry rock. However, no major historical mining operations are known to the area. The acidic streams undergo neutralization in pH …

Using Naturally Occurring Radon 222 As A Tracer To Quantify Groundwater Fluxes To Streams, Mandy Machinal

Graduate Theses & Non-Theses

Naturally occurring radon in groundwater was used to test radon mixing models. Two different mixing models were used to quantify groundwater fluxes to streams; an analytical solution and a finite difference method. Two different bodies of waters were used in this study. The first location was Johnson Creek located in Grant-Kohrs Ranch in Deer Lodge, Montana. This is a small creek where lots of sampling points were taken. The stretch of Johnson Creek where radon samples were collected was about 0.34 km long with a flowrate between 0.01 m3/s and 0.017 m3/s. The second location was Merced River located in …

Mineralogy And Environmental Geochemistry Of Slag In Lower Area One, Butte, Montana, Jenna Kaplan

Graduate Theses & Non-Theses

Butte, Montana is the host to a Cu-Mo porphyry deposit and has been a location of mining interest since 1864. Once copper ore is removed from this deposit it goes through a smelting process. Copper smelting processes consist of roasting, smelting, concentrating, and fire refining. During smelting, metals are separated from the waste, or gangue material. Slag is the waste material from these processes. Non-ferrous slag, such as a copper ore, removes iron and silica from the original ore. There is much interest in slag postproduction for there is often still a significant weight percent of metals trapped within a …

Geochemical Assessment And Separation Of Source Waters In The Upper Boulder River Watershed Near Boulder, Mt, John Anderson

Graduate Theses & Non-Theses

Environmental samples were collected at three surface water sites between 5/21/2011 and 11/21/2014 along the Upper Boulder River near Boulder Montana. The sites were located at Bernice (within the mountain block), near the High Ore drainage (near the mountain block/basin transition), and at the USGS Gauging Station near Boulder, Montana (within the basin). The parameters measured in the field were SC, temperature, and alkalinity with occasional pH measurements. We collected samples for anions, cations, and stable isotopes in the catchment. We identified endmembers by sampling snow and groundwater and determined from available data an approximate endmember for rain, snow, and …

Biogeochemical Cycling In A Headwater Stream And Riparian Zone, A. Capri Gillam

Graduate Theses & Non-Theses

Several teams of researchers at multiple universities are currently measuring annual and seasonal fluxes of carbon dioxide and other greenhouses gases (nitrous oxide and methane) in riparian wetlands and upland forests in the Tenderfoot Creek Experimental Forest (TCEF), a subalpine watershed in the Little Belt Mountains, Montana. In the current thesis, the author characterized the geochemistry and stable carbon isotope composition of shallow groundwater, soil water, and stream water in upper Stringer Creek, near sites that are being investigated for gas chemistry and microbial studies. It was hypothesized that if methanogenesis were a dominant process in the riparian wetlands of …