An isotopic study of a fluvial-lacustrine sequence: The Plio-Pleistocene koobi fora sequence, East Africa
Links
- More information: Publisher Index Page (via DOI)
- Download citation as: RIS | Dublin Core
Abstract
Stable isotopic analyses of Plio-Pleistocene and modern sediments in the fluvial-lacustrine system occupying the Turkana Basin, East Africa provide constraints on the paleoenvironmental and diagenetic histories of the Pliocene through the Recent sediments in the basin. The δ13C values for carbonates in lacustrine sediments range from −15 to +22‰ relative to PDB, depending on the varying proportions of CO2 from the atmospheric reservoir and from various metabolic sources. The δ18O values of carbonates in lacustrine sediments indicate that the isotopic composition of paleolake water varied by over 10‰ from the Pliocene to the present. The δ13C values for pedogenic carbonates record paleoccologic variations and suggest that C4 plants did not become well established in the preserved depositional parts of the basin until about 1.8 myr ago. The δ18O values pedogenic carbonates suggest a range of over 10‰ for the isotopic composition of soil water during this interval. They also suggest a period of major climatic instability from about 3.4 to 3.1 myr and at about 1.8 myr. Together, the δ13C and δ18O values of pedogenic carbonates indicate that the present conditions are as arid and hot as any that had prevailed during deposition of these Plio-Pleistocene sediments.
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | An isotopic study of a fluvial-lacustrine sequence: The Plio-Pleistocene koobi fora sequence, East Africa |
| Series title | Palaeogeography, Palaeoclimatology, Palaeoecology |
| DOI | 10.1016/0031-0182(88)90104-6 |
| Volume | 63 |
| Issue | 4 |
| Year Published | 1988 |
| Language | English |
| Publisher | Elsevier |
| Description | 22 p. |
| First page | 335 |
| Last page | 356 |
| Country | Ethiopia, Kenya |
| Other Geospatial | Lake Turkana Basin |