Quaternary Coasts of the United States: Marine and Lacustrine Systems

Quaternary Coasts of the United States: Marine and Lacustrine Systems Project #274 Quaternary Coastal Evolution - This Special Publication represents the major cumulative contribution of the Working Group of the United States of America to IGCP Project 274. The primary aims of Project 274 are to: (1) document and explain local to global variations in coastal and continental-shelf evolution, incorporating knowledge of coastal and shelf processes and environment with geodynamic, climatic, oceanographic and other data to produce local and regional models, ranging from descriptive to numerical, leading to a better understanding of interactive forces responsible for past, present and future changes to the coasts of the world; and (2) promote specified thematic studies, which are necessary to solve problems of coastal change affecting human occupation of the coastal zone. The volume contains sections on Atlantic, Pacific, Gulf and Lacustrine shorelines, covering both Holocene and Pleistocene deposits, representing a summary of decades of research into coastal and continental-shelf evolution of North America.
Obliteration of Surficial Paleolake Evidence in the Tule Valley Subbasin of Lake Bonneville
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Published:January 01, 1992
Abstract
This paper analyzes the extent of preserved and obliterated paleolake shoreline and sediment evidence in the Tule Valley subbasin of Lake Bonneville. It identifies the dominant processes responsible for effacing the paleolake evidence and estimates long-term average obliteration rates. Temporal control is provided by the well-constrained reconstructed chronology of Lake Bonneville.
Erosion associated with alluvial-fan processes is overwhelmingly responsible for the partial obliteration of the studied shorelines. Long-term average shoreline-obliteration rates vary from 3.0 to 5.7 percent per 1,000 yrs. Extent of preservation increases with the strength of a shoreline’s geomorphic development.
Measurements of the areal extent of all lacustrine and nonlacustrine Quaternary deposits below the highest shoreline reveal that 57 percent of the paleolake sediments have been removed from surface exposure since the start of Lake Bonneville regression. This yields a long-term average obliteration rate of 3.9 percent (47 km2) per 1,000 yrs. Alluvial-fan and eolian processes are responsible for 89 and 11 percent, respectively, of the removal of paleolake sediments from surficial exposure in Tule Valley.