USGS Open-File Report 01-282 -- Table 4

Open-File Report 01-282

Sediment-Deposition Rates and Organic Compounds in Bottom Sediment at Four Sites in Lake Mead, Nevada, May 1998

Table of Contents | Conversion Factors and Chemical Abbreviations | Report Home Page

Table 4. Depth of the pre-impoundment boundary and the 1952 and 1964 cesium-137 peaks, and sediment-deposition rates in bottom-sediment cores at four sites in Lake Mead, May 1998

[Abbreviations: (g/cm²)/yr, grams¹ per square centimeter per year; ND, not determined]

Site number	Depth in core (centimeters)			Sediment deposition rates ((g/cm2)/yr)
Site number	Pre-impoundment boundary	1952 cesium-137 peak²	1964 cesium-137 peak³	Pre-impoundment to 1952	1952-64	1964-98	Pre-impoundment to 1998
Site 1: Las Vegas Bay -- shallow	⁴116	112.5	87.5	0.41	1.68	1.81	1.45
Site 2: Las Vegas Bay -- deep	⁵118	92.5	62.5	1.11	1.44	1.26	1.25
Site 3: Overton Arm	⁶75	69.75	⁷ND	.25	⁷ND	⁷ND	.80
Site 4: Colorado and Virgin Rivers confluence (pre-impoundment)	⁸85	52.25	20.5	1.03	1.27	.26	.65

¹ Grams in dry weight.
² Cesium-137 first appeared in the atmosphere about 1952.
³ Cesium-137 peaked in the atmosphere about 1963-64.
⁴ April 1937.
⁵ June 1935.
⁶ June 1936.
⁷ Not determined because of the many peaks that occur within the core (Jennifer T. Wilson, U.S. Geological Survey, oral commun., 1999).
⁸ May 1935.