CHARACTERISTICS OF 2 LANDSLIDE-DAMMED LAKES IN A GLACIATED ALPINE ENVIRONMENT

Two young landslide-dammed lakes in a remote portion of Glacier Nation al Park, Montana, were studied to determine if their characteristics a re similar to those of older glacial lakes. We sampled lake depth alon g longitudinal transects and collected lake-bottom sediments for exami nation of particle size, organic matter content, and presence of benth ic vegetation. Water-quality data were also analyzed. The older Slide Lake has a less steep bottom and supports benthic vegetation; the youn ger Slide Pond, with a steep bottom profile, does not. Organic matter content and sediment textural characteristics were a function of locat ion in each lake, particularly in terms of proximity to each of the la ndslide dams. Although geomorphically different in terms of origin fro m glacially scoured lakes, the water-quality characteristics of the la ndslide-dammed lakes are similar to those of small glacial lakes in th e park.