caa a22 4500 469077549 CHVBK 20180323132939.0 cr unu---uuuuu 170328e19920101xx s 000 0 eng 10.1007/BF00197029 doi (NATIONALLICENCE)springer-10.1007/BF00197029 Fossil diatoms and the mid to late holocene paleolimnology of Lake Turkana, Kenya: a reconnaissance study [Elektronische Daten] [John Halfman, David Jacobson, Carolyn Cannella, Kurt Haberyan, Bruce Finney] A 12 m sediment core recovered from the south basin of Lake Turkana, northwestern Kenya, reveals four major diatom assemblages that span approximately 5450 to 1070 years BP based on AMS radiocarbon analyses. The oldest assemblage, Zone D (5450 to 4850 yr BP), is dominated by Melosira nyassensis and Stephanodiscus spp. and is interpreted to reflect higher lake levels, fresher water and more variable seasonal mixing of the water column than the modern lake. Melosira dominates the assemblage in Zone C (4850 to 3900 yr BP) with some Surirella engleri and Stephanodiscus. This assemblage indicates a continuation of relatively high lake levels and seasonal mixing of a stratified lake. The brief peak of Surirella, interpreted as benthic, suggests an episode of slightly lower lake level. Thalassiosira rudolfi and Surirella predominate since the beginning of Zone B (3900 to 1900 yr BP), reflecting a decrease in lake level and increase in water column salinity. Increasing dominance of Surirella in Zone A (1900 to 1070 yr BP) may suggest that the lake continued to decrease in depth. Salinity probably rose to levels comparable with the modern lake. These results are consistent with paleoclimatic interpretations based on carbonate abundance, lamination thickness, oxygen isotope and bulk geochemistry profiles from this core and cores recovered from the north basin. It extends the known paleolimnology beyond 4000 yr BP of the earlier research to 5450 yr BP and into the early to mid Holocene pluvial phase in northern intertropical east Africa. Kluwer Academic Publishers, 1992 diatoms nationallicence paleolimnology nationallicence paleoclimatology nationallicence sediments nationallicence radiocarbon chronology nationallicence East Africa (Kenya) nationallicence Halfman John Department of Civil Engineering and Geological Sciences, University of Notre Dame, 46556-0767, Notre Dame, IN, USA aut Jacobson David Department of Civil Engineering and Geological Sciences, University of Notre Dame, 46556-0767, Notre Dame, IN, USA aut Cannella Carolyn Department of Civil Engineering and Geological Sciences, University of Notre Dame, 46556-0767, Notre Dame, IN, USA aut Haberyan Kurt Department of Biology, Troy State University, 36082-0001, Troy, AL, USA aut Finney Bruce Institute of Marine Science, University of Alaska, 99775-1080, Fairbanks, AK, USA aut Journal of Paleolimnology Kluwer Academic Publishers 7/1(1992-01-01), 23-35 0921-2728 7:1<23 1992 7 10933 https://doi.org/10.1007/BF00197029 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00197029 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Halfman John Department of Civil Engineering and Geological Sciences, University of Notre Dame, 46556-0767, Notre Dame, IN, USA aut NATIONALLICENCE 700 1- Jacobson David Department of Civil Engineering and Geological Sciences, University of Notre Dame, 46556-0767, Notre Dame, IN, USA aut NATIONALLICENCE 700 1- Cannella Carolyn Department of Civil Engineering and Geological Sciences, University of Notre Dame, 46556-0767, Notre Dame, IN, USA aut NATIONALLICENCE 700 1- Haberyan Kurt Department of Biology, Troy State University, 36082-0001, Troy, AL, USA aut NATIONALLICENCE 700 1- Finney Bruce Institute of Marine Science, University of Alaska, 99775-1080, Fairbanks, AK, USA aut NATIONALLICENCE 773 0- Journal of Paleolimnology Kluwer Academic Publishers 7/1(1992-01-01), 23-35 0921-2728 7:1<23 1992 7 10933 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer