| Description |
Limiting the range of natural climate variability as well as characterizing the patterns of climate change at a variety of spatiotemporal scales have emerged as critical goals within the Earth sciences. Instrumental records provide valuable benchmarks but lack sufficient temporal coverage to adequately address these questions. Therefore, records of past climate oscillations preserved within geologic archives have proven to be indispensable towards answering these fundamental questions. And while investigations of past climate oscillations at the global scale are important, they often lack sufficient fidelity to accurately characterize regional changes. Characterizing the magnitude and frequency of past climate changes, particularly hydroclimate, is critically important for semi-arid regions with rapidly increasing human populations like the Great Basin of Western North America. This dissertation presents results from three studies focusing on developing high spatial and temporal resolution records of Late Pleistocene to Early Holocene glacier and climate changes in the Great Basin. The primary area of interest for all three studies is the Wasatch Mountains of Utah where abundant and well-preserved glacial, cave, and lacustrine deposits are collocated. Each of these studies attempts to qualitatively and sometimes quantitatively limit the style and magnitude of climate changes within the region and their connections to global events. Based on the Wasatch Range records, the region experienced a wide array of iv climatic changes from the Last Glacial Maximum (LGM) to the Early Holocene. During the LGM, the region was relatively cold and dry, which nourished glaciers that had advanced to the western front of the range before retreating near the end of the LGM. Following the close of the LGM, a relatively warmer and wetter Lateglacial period persisted and allowed glaciers to readvance nearly to their respective LGM positions. However, rising global temperatures forced glaciers to retreat to half of their maximum lengths before retreating from these positions around ca. 15 ka. The Timpanogos Cave record suggests that the Great Basin during Latest Pleistocene to Early Holocene (ca. 10.5-13.6 ka) was characterized by notable climate oscillations that were mixed in their connections to global climate change events, underscoring the need for regional investigations. |
