Tag Archive for: Lake Bonneville
Researchers sifting through deposits of owl pellets in Utah’s Homestead Cave have discovered that small-mammal communities scurrying around the West Desert remained stable through millennia of climate change.
By: Daren T. Nelson and Paul W. Jewell
The Hogup Bar quadrangle is located southeast of Park Valley, Utah, and west of the northwest arm of Great Salt Lake. Late Pleistocene Lake Bonneville sediments and related shorelines dominate the landscape, and record the transgression and regression of Lake Bonneville. Surficial deposits overlie Tertiary basalt and Permian-Pennsylvanian sedimentary bedrock.
While the weather has been warm, and there’s not a lot of snow or ice around, it’s a great time of year to look at the Ice Age animals of Utah. Did you know that Great Salt Lake is the remnant of Ice Age lake, Lake Bonneville? Read more about this different age in Utah in our “Popular Geology” subjects HERE.
The Pony Express basaltic ash is locally a useful stratigraphic marker in Lake Bonneville sediments in west-central Utah. The ash was erupted from a vent in the Sevier Desert basin soon after Lake Bonneville had transgressed high enough to flood into the basin about 24,000 years ago. The ash is found at or near the base of the Bonneville marl below altitudes of 1400m (4600 ft) in part of the Sevier Desert basin and the southernmost part of the Great Salt Lake basin. The chemical composition of the ash is similar to that of other basalts in the Sevier Desert. Possible source vents are in the Pahvant Butte area or a maar near Smelter Knolls.
This CD contains a 10-page report in PDF format. The latest version of Adobe Reader is required to view the PDF files.
Adam McKean, one of our Geologists here at the Utah Geological Survey, is featured as a guest author on the blog The Traveling Geologist. Check it out!
Urban geologic mapping may sound like a mapping geologist’s nightmare with all the private property, disturbed land, and development rapidly covering up the geology. Despite these difficulties, my experience with it has been exciting and challenging. Why map geology in and near the city? The simple answer is that urban areas need surficial geologic maps to aid in geologic-hazard identification and mitigation. Additionally, a good geologic map provides the basic geologic information needed for further geologic, groundwater, geotechnical, and engineering investigations.
This quadrangle is located in central Utah within the eastern Basin and Range Province. The quadrangle includes the northern part of Utah Lake in western Utah Valley, the northern and northeastern lakeshore, and Pelican Point, extending into Utah Lake from the eastern edge of the Lake Mountains. Bedrock near Pelican Point includes Mississippian-age sedimentary strata on the eastern limb of the Lake Mountains syncline. The majority of the quadrangle is covered by Utah Lake, which is underlain by normal faults that form the western boundary of Utah Valley. Surficial deposits along the lakeshore are primarily associated with lacustrine deposition from Holocene Utah Lake and its precursor, late Pleistocene Lake Bonneville.
CD (2 pl., 1:24,000)