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Marine Geology Data

Univ. of Minnesota, Large Lakes Observatory
Lake Victoria Cruise V95 Cores
Biogenic Silica and Carbon 14 Age Dates

NGDC Data Set G02885



Biogenic Silica Data and 14C dates from Lake Victoria Sediments

The LLO operates in conjunction with the Limnological Research Center (LRC) in working towards fulfilling the objectives of the International Decade for the East African Lakes (IDEAL) to study the East African Lakes. The Lake Victoria project is funded by NSF. Like Lake Victoria, extensive work is being continued on Lake Malawi, Lake Turkana, and Lake Edward. In addition to the East African lakes, the LLO is working on Lake Issyk Kul', Lake Nicaragua, and Lake Superior.

SUMMARY: The Biogenic Silica Data file contains data for 5 cores taken from various sites in Lake Victoria. The data include ship, coring date, water depth, latitude/longitude, sampling device, sampled interval, % biogenic silica, and 14C dates. Cores were sampled at 10 cm intervals for biogenic silica analysis. Samples taken for 14C dating were prepared at the LRC Laboratory and sent to an outside AMS Facility for analysis. Pollen, charcoal, and plant macrofossils were dated.

Method for Biogenic Silica Analysis:

Biogenic Silica analysis was done using a timed, wet extraction technique adapted from D. J. DeMaster (1979). The analysis was done using 0.5 M NaOH at 85 0C.

These data were produced by the:

Large Lakes Observatory (LLO)
University of Minnesota, Duluth
213 Research Laboratory Building
2205 East 5th Street
Duluth, MN 55812-2401

Related References:

DeMaster, D.J. (1979) , The Marine Budgets of Silica and 32Si. Ph. D. Thesis, Yale University. pp 246-264.

Johnson, T. C., C. A. Scholz, M. R. Talbot, K. Kelts, R. D. Ricketts, G. Ngobi, K. Beuning, I. Ssemmanda and J. McGill, 1996. Late Pleistocene desiccation of Lake Victoria and rapid evolution of cichlid fishes. Science, v.273, p. 1091-1093...

Beuning, K., K. Kelts and T. C. Johnson, in press. Paleohydrology of Lake Victoria, East Africa inferred from 18O/16O ratios in sediment cellulose. Geology.

Johnson, T. C., Y. Chan, K. Beuning, K. Kelts, G. Ngobi and D. Verschuren, in press. Biogenic silica profiles in Holocene cores from Lake Victoria: implications for lake level history and initiation of the Victoria Nile. In: Lehman, J. T. (Editor), Environmental Change and Response in East African Lakes. Kluwer Press, Amsterdam.

Verschuren, D., D. N. Edgington, H. J. Kling and T. C. Johnson, in press. The eutrophication of Lake Victoria: sedimentary signals at offshore stations. Journal of Gt. Lakes Research.

Scholz, C. A., T. C. Johnson, P. Cattaneo, H. Malinga and S. Shana, in press. Initial results of 1995 IDEAL seismic reflection survey of Lake Victoria, Uganda and Tanzania. In: Lehman, J. T. (Editor), Environmental Change and Response in East African Lakes. Kluwer Press, Amsterdam.


NGDC/WDC GMG, Boulder archives a wide variety of digital marine geology data collections, paper reports, microfilm, etc. containing sediment and hardrock data. Many of the digital files are available for direct download. Sample-by-sample inventory information for all data, regardless of format available from NGDC are fully searchable through the marine geology inventory (GEOLIN).