Document Type
Thesis
Abstract
The Fish Lake Plateau of south-central Utah is underlain by a thick sequence of Tertiary volcanics and sedimentary rocks. The Fish Lake Plateau was glaciated at least twice during the Pleistocene. The UM Creek drainage basin is located in the northeastern Fish Lake Plateau at elevations between 3540 — 2440 m. UM Creek flows south through an elongate N-S trending basin with a drainage area of ~110 km’ that empties into the Fremont River. The structural geometry of the UM Creek basin is dominated by NNW and NE trending grabens and their bounding normal faults. Geologic mapping in the northeastern Fish Lake Plateau reveals abundant surficial deposits overlying Tertiary bedrock units. Many of these Quaternary deposits formed due to landslide and mass wasting associated with the failure of weak silty limestones in the Flagstaff Formation. The upper UM Creek basin is extensively mantled by surficial deposits, whereas in the south, lower UM Creek flows over a bedrock channel. Geologic mapping, sediment core analysis, and kinematic GPS data suggest that Water Flat a ~1 km” low-relief flat was dammed by a large landslide event that covers ~3 km* and is underlain by shallow lacustrine deposits. Faulting reversed the southward drainage of an ancestral Fremont River before UM Creek incised and reintegrated stream flow. In addition, another large mass movement landslide was mapped that covers ~3.5 km’. Danish Meadows, an elongate ~2 km’ flat, formed by Quaternary slip on a cross fault that temporarily truncated the UM Creek drainage. Faulting and subsequent mass wasting causes the creation of many of the low-relief flats on the northeastern Fish Lake Plateau. In the upper UM Creek basin the Potholes, a topographically hummocky south-facing feature (~2820 m), forms a prominent terminal moraine complex. Three trachyandesite boulders were sampled along the crest of the Potholes moraine for “He exposure age dating using pyroxenes. Pending results from mass spectrometry analysis, exposure ages likely correlate with the Last Glacial Maximum (ca.18-20 ka) ages obtained from similar moraines on the Fish Lake Plateau.
Date Awarded
2007
Department
Geology
Advisor 1
Christopher M. Bailey
Recommended Citation
Haug, Eric W., "Surficial Geology of the UM Creek drainage Basis, Fish Lake Plateau, Utah: Glaciation, Tectonics, and Mass Wasting" (2007). Geology Senior Theses. William & Mary. Paper 175.
https://scholarworks.wm.edu/geologyseniors/175
