Individual ostracode valve analyses of Sclerocypris clavularis from modern Lake Turkana sediments

DOI

We provide stable carbon (δ¹³C) and oxygen (δ¹⁸O) isotope measurements in individual calcitic valves of extant ostracode species, Sclerocypris clavularis, from modern sediments in 17 sites across Lake Turkana, eastern Africa. These sediments were collected using a modified Ekman dredge during May-November, 1979. Pooled statistics of these individual ostracode valve analyses (IOVA) of δ¹³C and δ¹⁸O measurements (n = 329) at each site show strong correlations with lake hydrological parameters. Within-site variance in IOVA-δ¹³C is larger (~60%) than that of IOVA-δ¹⁸O. Yet, pooled averages exhibit a systematic pattern with higher δ values towards the southern part of the lake, away from Omo River inflow, which is the largest riverine input into Lake Turkana (comprising ~90% of overall inflows). We suggest that the latitudinal δ¹³C gradient may arise from low riverine δ¹³C and low organic matter δ¹³C as a productivity response to nutrient-rich Omo River inflow towards the north. The δ¹⁸O pattern may be explained by the diminishing influence of Omo River inflows and more evaporation driving higher IOVA-δ¹⁸O values towards the windier, southern basin. We conclude that pooled IOVA statistics in Omo-Turkana sediments can aid interpretations of past regional paleohydrology and its variability in this basin.

Identifier
DOI https://doi.org/10.1594/PANGAEA.958974
Related Identifier https://doi.org/10.1029/2022GC010790
Related Identifier https://doi.org/10.5281/ZENODO.7854022
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.958974
Provenance
Creator Thirumalai, Kaustubh ORCID logo; Cohen, Andrew N; Taylor, Dustin ORCID logo
Publisher PANGAEA
Publication Year 2023
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Bundled Publication of Datasets; Collection
Format application/zip
Size 2 datasets
Discipline Earth System Research
Spatial Coverage (35.853W, 2.738S, 36.627E, 4.361N)
Temporal Coverage Begin 1979-05-01T00:00:00Z
Temporal Coverage End 1979-11-30T00:00:00Z