气候变化领域集成服务门户(CCPortal): Aquatic biomarkers record Pleistocene environmental changes at Paleolake Olduvai; Tanzania

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DOI	10.1016/j.palaeo.2019.04.001
	Aquatic biomarkers record Pleistocene environmental changes at Paleolake Olduvai; Tanzania
	Colcord D.E.; Shilling A.M.; Freeman K.H.; Njau J.K.; Stanistreet I.G.; Stollhofen H.; Schick K.D.; Toth N.; Brassell S.C.
发表日期	2019
ISSN	0031-0182
起始页码	250
结束页码	261
卷号	524
英文摘要	Several hypotheses invoke climatic variability as a driving force for hominin evolution. Thus, high-resolution records of climate and environmental variability from anthropologically significant locations can help test these hypotheses. Sedimentary sequences recovered by the Olduvai Gorge Coring Project (OGCP) help evaluate climatic and environmental changes at Olduvai Gorge, Tanzania through the analyses of various biogeochemical proxies. The stratigraphic sequence of OGCP Core 2A can be correlated with horizons associated with hominins and is chronologically constrained by distinctive dated horizons, such as the Bed I Basalt and Tuff IB. The lacustrine interval from 76.6 to 86.9 m depth is ideally suited for high-resolution analyses of biogeochemical proxies as it is rich in organic carbon (>1%TOC). The hydrogen isotopic composition of nC31 in this interval of OGCP Core 2A records the effects of precession-driven wet-dry cycles on the terrestrial environment that led to alternations between woodland and grassland ecosystems, comparable to those documented by previous investigations of outcrop analogues at Olduvai. Here, we examine stratigraphic variations in the abundance of biomarkers (C28 steradienes, C17 and C23 n-alkanes, C27 and C28 A-norsteranes, fern-8-ene, and chromans) derived from aquatic organisms (algae, cyanobacteria, sponges, macrophytes, etc.) to determine the response of Paleolake Olduvai to climate variability. In general, these aquatic biomarkers reflect the productivity of the lake environment and exhibit the same precession-driven wet-dry cycles recorded by terrestrial biogeochemical signatures. However, they also provide evidence of abrupt (<~300 yr) changes in lake level and corresponding aquatic communities superimposed on the longer-term Milankovitch cycles. Thus, evidence for climatic variability is manifested through the pacing and intensity of changes in both terrestrial and aquatic ecosystems, but the different rates of the responses on land and in the aquatic environment potentially had a complex influence on water and food resources that were important factors for hominin habitation and evolution. © 2019 Elsevier B.V.
英文关键词	Biomarkers; Hominin evolution; Lacustrine sediments; Sediment core
语种	英语
scopus关键词	anthropogenic effect; aquatic environment; biochronology; biogeochemistry; chronosequence; climate variation; environmental change; historical record; hominid; human evolution; isotopic composition; lacustrine deposit; paleoenvironment; paleohydrology; Pleistocene; sediment core; sedimentary sequence; Arusha [Tanzania]; Olduvai Gorge; Tanzania; algae; Cyanobacteria; Filicophyta
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150965
作者单位	Department of Earth and Atmospheric Sciences, Indiana University, Bloomington, IN, United States; Department of Geosciences, The Pennsylvania State University, University ParkPA, United States; Department of Earth and Ocean Sciences, University of Liverpool, Liverpool, United Kingdom; GeoZentrum Nordbayern, Friedrich-Alexander-Universität (FAU), Erlangen, Germany; The Stone Age Institute, Gosport, IN, United States
推荐引用方式 GB/T 7714	Colcord D.E.,Shilling A.M.,Freeman K.H.,et al. Aquatic biomarkers record Pleistocene environmental changes at Paleolake Olduvai; Tanzania[J],2019,524.
APA	Colcord D.E..,Shilling A.M..,Freeman K.H..,Njau J.K..,Stanistreet I.G..,...&Brassell S.C..(2019).Aquatic biomarkers record Pleistocene environmental changes at Paleolake Olduvai; Tanzania.Palaeogeography, Palaeoclimatology, Palaeoecology,524.
MLA	Colcord D.E.,et al."Aquatic biomarkers record Pleistocene environmental changes at Paleolake Olduvai; Tanzania".Palaeogeography, Palaeoclimatology, Palaeoecology 524(2019).