EARLY OBSERVATIONS OF A GEOMORPHIC ANALYSIS REGARDING PROXIES THAT INDICATE PALEOWAVE ENERGY DISTRIBUTION IN THE BONNEVILLE BASIN

The well-developed lacustrine landforms formed during the Late Pleistocene highstand of the pluvial Lake Bonneville in northwestern Utah demonstrate the complexity and diversity of coastal features in the Bonneville Basin. In various localities in the basin lacustrine features, such as wave platforms and beach ridges, are being mapped and analyzed to refine the chronology of minor lake level fluctuations and to understand the factors that affected the distribution of wave energy. The mapping of the distribution of bedrock/sediment controlled platforms, tufa development, orientation of landforms (i.e. spits, bars, tombolos, beach ridges, and wave platforms), and sediment transport, (provenance, grain size distribution, and source/supply) indicate that the largest and most erosive waves originated from the north and were primarily transporting sediment in a southerly direction. Since wave action is a direct consequence of wind speed and direction these observations indicate that the dominant wind and storm tracks were most likely coming from the north. These observations provide additional evidence that strong katabatic winds (Jewell, 2007 in press) may have been coming off the ice sheet to the north of the lake and affected the local climate and landform development. In addition, land surveys (in progress) and recent airborne LiDAR acquisitions are providing very detailed elevation controls and profiles that provide detailed datasets for modeling the paleowave conditions required for the formation of wave platforms and coarse grained beach ridges. The wave energy distribution of these landforms should then provide additional constraints on the conditions of the local climate during the Late Pleistocene.