Abstract

Travertine, a carbonate mineral formed by precipitation of spring water, is found at many localities in the western United States. Most travertine is precipitated by bacteria or algae, and is associated with hot or cold springs proximal to faults. Travertine deposits in the Pavant Valley of central Utah, informally called the Black Rock travertine, are associated with a series of northeast trending hot springs (up to 63 degrees C). The springs and travertine are in close proximity to, and follow the same general linear trend as, the Pavant thrust, and the Kanosh volcanic field. The gross morphology of the travertine is dominated by long fissure ridges. Other prominent structures include terraces, sloping mounds, and raised pools. The microstructures, and the internal stratification of the travertine, depend upon the type of travertine accumulation.

Bacterial and algal shrubs, stromatolites, casts of algal and bacterial filaments, and bacterial clumps are found in biochemically precipitated travertine. Euhedral crystalline travertine is characteristic of physiochemical deposition. Modern deposition of the Black Rock travertine is dominated by biochemical precipitation.

The Black Rock travertine, post-Lake Bonneville in age, has preserved Quaternary animal remains including beetles (Order Coleoptera, Family Hydrophilidae), an American Avocet (Recurvirostra americana), and bison (Bison sp.).