Link to USGS home page.
Open-File Report 2005–1288
  About USGS /  Science Topics /  Maps, Products & Publications /  Education / FAQ

Stratigraphy of Lacustrine Sediments Cored in 1996, Bear Lake, Utah and Idaho

By Steven M. Colman

thumbnail image of figure 1 in report: generalized map of Bear Lake

The overall goal of our research on Bear Lake is to create records of past climate change for the region, including changes in precipitation (rain and snow) patterns during the last 10,000 years and longer. As part of the project, we are attempting to determine how the size of Bear Lake has varied in the past, to assess the possibility of future flooding and drought. We also seek to understand human influences on sediment deposition, chemistry, and life in the lake.

Evidence of past conditions comes from sediments deposited in the lake, so reconstruction of past conditions requires accurate dating of the sediments. The study includes the upper Bear River watershed as well as Bear Lake itself. The Bear River is the largest river in the Great Basin and the source of the majority of water flowing into the Great Salt Lake. In this region, wet periods may produce flooding along the course of the Bear River and around Great Salt Lake, while dry periods, or droughts, may affect water availability for agricultural, industrial, and residential use.

This report describes the stratigraphy of sediments beneath Bear Lake along a transect of cores obtained in 1996. The stratigraphy is derived mostly from high-resolution acoustic-reflection profiles, supplemented by analytical information from cores that indicate correlations among various horizons. The deep drill hole obtained in 2000 (BL00-1) also is along the same acoustic profile, so the stratigraphy of its upper part also is described in relation to the 1996 cores.

Version 1.0

Posted August 2005

Part or all of this report is presented in Portable Document Format. The latest version of Adobe Acrobat Reader or similar software is required to view it. If you wish to download the latest version of Acrobat Reader free of charge, click here.


For viewing and printing upon download.
(This version of the report is accessible as defined in Section 508 of the Rehabilitation Act of 1973, Amendments of 1998.)

USA.gov logo