Text

theses

Lacustrine records are powerful achieves of terrestrial paleoclimate and paleoenvironment as they are highly sensitive to small-scale changes in a given system. Located in the heart of one of the richest Plio-Pleistocene fossil localities, the Turkana Basin has long been of interest to scientists seeking to understand the climatic conditions surrounding our species’ origins. Additionally, at present this semi-arid region hangs in a delicate balance due to global climate change and anthropogenic impacts threatening to forever alter Lake Turkana’s ecosystems. Understanding the system as it is today is essential for unlocking the full potential of the paleorecords. This study increases the understanding of how changes in paleoenvironment and paleoclimate are preserved in lacustrine sediments by applying lessons learned and models developed from a) modern/Common Era studies to the paleorecords of b) the Holocene Lake Turkana highstand, c) the Pleistocene Lorenyang Lake from the West Turkana Kaitio drill core (WTK). Each interval was studied either from cores or outcrops independently before being synthesized to analyze Turkana system through space and time. I produced sedimentological and stratigraphic descriptions (including a detailed facies model for the WTK core), generated high-resolution ostracod assemblages, and collected stable isotope data on ostracods from each time interval. Ultimately, my research demonstrates that ostracods are sensitive to hydrological changes, particularly, lacustrine transgressions and/or regressions through otherwise sedimentologically homogeneous intervals. This demonstrates the potential for this kind of high-resolution study to better understand the roll that paleoclimatic and paleoenvironmental oscillations might have played in early hominin evolution.

ETD_6582

Ph.D.

Includes bibliographical references

by Catherine Clifford Beck

doi:10.7282/T3ZS2ZGB

ETD doctoral

The author owns the copyright to this work.