Reconstruction of Pliocene-Pleistocene Sediment Sources and Weathering Intensity in the Paleo-Life Rich Olduvai and Laetoli Basins of Northern Tanzania Using Major and Trace Element Geochemistry and Sr Isotopic Data

Simple item page
dc.contributor.authorKasanzu, Charles H.
dc.contributor.authorMaboko, Makenya A. H.
dc.contributor.authorManya, Shukrani
dc.date.accessioned2016-08-04T16:22:15Z
dc.date.available2016-08-04T16:22:15Z
dc.date.issued2016-07
dc.descriptionFull text can be accessed at http://www.sciencedirect.com/science/article/pii/S1464343X16302485en_US
dc.description.abstractMajor and trace elements and Sr isotopic compositions were analyzed for samples from the Pliocene-Pleistocene to Recent Olduvai and Laetoli basins of northern Tanzania with the aim of constraining their provenance and paleo-climatic conditions. The Olduvai samples are characterised by La/Cr ratios of 0.69–3.73, Th/Sc = 1.12–24.6 and 87/Sr/86Sr = 0.70448–0.70563; features which suggest the volcanic facies of the nearby Olmoti as their possible source. The relatively lower values for the Laetoli basin (Th/Sc = 0.4–0.9 and 87/Sr/86Sr = 0.70412–0.70508) coupled with Zr/Nb, Nb/Ta ans Zr/Hf ratios are suggestive of a mafic protolith inferred to be the Sadiman lavas. The calculated Chemical Index of Alteration (CIA) values for the Laetoli samples are 58–78% (mean = 65%) indicating higher weathering intensities of the source compared to 45% in the Olduvai samples. The calculated Mean Annual Precipitation (MAP) values are higher at Laetoli (mean = 950 ± 181 mm/yr) relative to Olduvai (mean = 694 ± 181 mm/yr) consistent with increased rainfall in the Pliocene during the deposition of Laetoli strata when compared to the Pleistocene times when the Olduvai sediments were deposited. The CIA and MAP patterns observed at Laetoli and Olduvai can be related to temporal changes in weather conditions during the Pliocene and Pleistocene, respectively. The Lower CIA and MAP values at Olduvai imply the prevalence of arid to semi-arid climatic conditions during the Pleistocene whereas the higher values at Laetoli correspond with wetter conditions during the Pliocene times. This could have the potential for improved eutrophication at Laetoli. The climatic inferences drawn from CIA and MAP data may point to a more favourable habitat for life proliferation in the wetter environment of Laetoli compared to the drier Olduvai. This inference is consistent with archaeological evidence which indicates a greater abundance of hominin fossils including the well preserved footprints in Laetoli.en_US
dc.identifier.citationKasanzu, C., Maboko, M. and Manya, S. (2016). Reconstruction of Pliocene-Pleistocene sediment sources and weathering intensity in the paleo-life rich Olduvai and Laetoli basins of northern Tanzania using major and trace element geochemistry and Sr isotopic data. Journal of African Earth Sciences.en_US
dc.identifier.doi10.1016/j.jafrearsci.2016.07.019
dc.identifier.urihttp://hdl.handle.net/20.500.11810/3456
dc.language.isoenen_US
dc.publisherElsevieren_US
dc.subjectOlduvaien_US
dc.subjectLaetolien_US
dc.subjectCIAen_US
dc.subjectMAPen_US
dc.subjectPaleo-weatheringen_US
dc.subjectProtolithen_US
dc.titleReconstruction of Pliocene-Pleistocene Sediment Sources and Weathering Intensity in the Paleo-Life Rich Olduvai and Laetoli Basins of Northern Tanzania Using Major and Trace Element Geochemistry and Sr Isotopic Dataen_US
dc.typeJournal Article, Peer Revieweden_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Reconstruction of Pliocene-Pleistocene sediment sources and weathering .pdf
Size:
109.24 KB
Format:
Adobe Portable Document Format
Description:
Abstract
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Department of Geology