Theses and Dissertations at Montana State University (MSU)
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Item Addressing the state of Yellowstone National Park's geologic maps using traditional and novel approaches(Montana State University - Bozeman, College of Letters & Science, 2023) Kragh, Natali Ann; Chairperson, Graduate Committee: Madison MyersAccurate geologic mapping is especially important for public land, such as Yellowstone National Park, so land managers can mitigate safety risks, mindfully place infrastructure, and communicate scientific knowledge to the public. The geology of Yellowstone National Park (YNP) has been repeatedly mapped over the last century by multiple geologists with varying perspectives and mapping goals. The most recent efforts have resulted in a patchwork of twenty-one different scale maps (one 1:125,000, one 1:100,000, and nineteen 1:62,500). Presently, there exists significant promise of publishing a higher resolution, seamless map of YNP; however, it has become apparent that many of the current internal maps disagree along their shared boundaries. This study aims to address these discrepancies using both traditional and novel techniques and determine if mapping along boundaries is the best practice towards creating a seamless map. In total, 485 areas of disagreement, referred to here as boundary problems, were identified. During this study, 66 boundary problems were resolved. Each resolved boundary problem was aided by traditional mapping techniques (i.e., field mapping, field petrography, sample collection, and limited geochemistry and thin section work). However, some areas could not be addressed by field methods alone and required a more substantial analytical approach. Three "case studies" were chosen to highlight how geochemistry could aide in mapping in YNP: 1) a geochemical, textural, and age analysis of "dacite" units found throughout the north and northwestern portions of YNP and the Greater Yellowstone Region, 2) compiling a geochemical database to compare and correlate known rock units to unrecognized outcrops found in the field, 3) a novel technique using Pb isotopes in detrital plagioclase crystals from volcaniclastic units to establish a volcanic source for the units. These approaches resulted in varying success, but overall, lead to a better understanding of the work that needs to be done in YNP to publish an accurate, higher resolution geologic map. This work highlights the importance of reassessing older geologic maps and making necessary updates when the need is recognized, particularly along disagreeing shared boundaries using multiple techniques.Item The national forest imperative : a historical geography of national forest landscapes, northern Rockies, Montana(Montana State University - Bozeman, College of Letters & Science, 2014) Fockler, Matthew Neil; Chairperson, Graduate Committee: William WyckoffThe United States Forest Service manages over 193 million acres of American public land. Management of these landscapes is often contentious. National forests have emerged as landscapes where conflicting ideas about nature and complex value systems are displayed in tangible ways. Current research concerning public lands of the American West has recognized the necessity of attaching material, social, and landscape changes to larger theoretical and cultural structures. This dissertation informs these dialogues by exploring national forest landscape change along the Rocky Mountain Front region of the Crown of the Continent ecosystem in north-central Montana. Using the current Rocky Mountain Division of the Lewis and Clark National Forest as a case study, this research reconstructs landscape change associated with Forest Service management and connects these tangible landscape changes to larger national political, economic, and cultural drivers that shaped agency policies, the national economy, and American society. Furthermore, it explores how local forest users have influenced and shaped forest management and landscape change. In doing so, it draws parallels between these changes and larger American attitudes towards nature, suggesting in this process the role played by the national forests in that larger national narrative. Finally, this dissertation provides a methodology in which these place-based changes on the land can be stored and assessed within a historical geographic information systems (HGIS) database schema. By incorporating significant archival, landscape, and HGIS methodologies, this research finds that national forest landscapes are shaped by national and local cultural trends. The Forest Service has modified its management imperative to address these changes. National forest landscapes are therefore the result of a largely informal negotiation process between the Forest Service, other federal and state agencies and authorities, the public, and the natural world. National forest landscapes are shown to be meeting points where diverse and complex social relations and value systems are transferred to the landscape. This dissertation therefore provides a meaningful set of interpretive tools and a methodology for examining how America public land resources and the ecological world are valued and understood.