Paleohydrology of Lake Victoria, East Africa, inferred from18O/16O ratios in sediment cellulose

Kristina R.M. Beuning, Kerry Kelts, Emi Ito, Thomas C. Johnson

Research output: Contribution to journalArticle

40 Scopus citations

Abstract

δ18O values of aquatic cellulose preserved in a 7.6 m sediment core from near the center of Lake Victoria, East Africa, record a 13000 yr hydrological history of the basin. Relative to the pres- ent value (+3.4‰),highly elevated lake-water δ18O values of +8‰±2‰ from 13200 to 7250 14C yr B.P. indicate closed-basin conditions and precipitation:evaporation ratios much smaller than at present. An abrupt drop in the lake-water δ18O to 0 ‰ ± 1‰marks the rapid transition to an open basin between 7250 and 7150 1414C yr B.P. From 7140 to 5400 14C yr B.P. increasing lake-water δ18O values from 0‰ ± 1‰ to +5‰ are proposed to reflect outlet downcutting and a likely de- crease in relative humidity. These data have unexpectedly shifted our view of the timing of changes in the Lake Victoria water balance and imply a period of at least 10000 years (17000 to 7000 14C yr B.P.) when the Lake Victoria basin did not contribute waters to the main Nile River.

Original languageEnglish (US)
Pages (from-to)1083-1086
Number of pages4
JournalGeology
Volume25
Issue number12
DOIs
StatePublished - Jan 1 1997

Fingerprint Dive into the research topics of 'Paleohydrology of Lake Victoria, East Africa, inferred from<sup>18</sup>O/<sup>16</sup>O ratios in sediment cellulose'. Together they form a unique fingerprint.

  • Cite this