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Main Authors: Gebregiorgis, Daniel, Deocampo, Daniel M, Longstaffe, Fred J, Simpson, Alexandra M, Ashley, Gail M, Beverly, Emily J, Delaney, Jeremy S, Cuadros, Javier
Format: Dataset Open Access
Language:en
Published: PANGAEA 2020
Subjects:
Online Access:https://doi.org/10.1594/PANGAEA.910866
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author Gebregiorgis, Daniel
Deocampo, Daniel M
Longstaffe, Fred J
Simpson, Alexandra M
Ashley, Gail M
Beverly, Emily J
Delaney, Jeremy S
Cuadros, Javier
author_facet Gebregiorgis, Daniel
Deocampo, Daniel M
Longstaffe, Fred J
Simpson, Alexandra M
Ashley, Gail M
Beverly, Emily J
Delaney, Jeremy S
Cuadros, Javier
collection Datos científicos de ciencias marinas y ambientales
contents Most clay minerals in sedimentary environments have traditionally been considered to be of detrital origin, but under certain conditions, authigenic clay minerals can form at low temperature through the transformation of precursor clays or as direct precipitates from lake-water. Such clay minerals can hold important information about the prevailing climatic conditions during the time of deposition. We present the first quantitative reconstruction of salinity in paleolake Olduvai based on the oxygen-isotope composition of authigenic clay minerals. We provide a framework illustrating that the isotopic signature of authigenic lacustrine clay minerals is related to the isotopic composition of paleo-waters, and hence to paleosalinity. This new paleosalinity proxy shows that the early Pleistocene East African monsoon was driven by combinations of precession and obliquity forcing, and subsequent changes in tropical SSTs. Such quantitative lacustrine paleosalinity estimates provides a new direction of research for modeling ecosystem change based on an ecologically relevant parameter.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_910866
institution PANGAEA
language en
publishDate 2020
publisher PANGAEA
record_format pangaea
spellingShingle Relative proportions of smectite and illite, and illite-smectite oxygen-isotope compositions (δ18OI-S) of 39 mudstone samples collected from a lacustrian section at Paleolake Olduvai
Gebregiorgis, Daniel
Deocampo, Daniel M
Longstaffe, Fred J
Simpson, Alexandra M
Ashley, Gail M
Beverly, Emily J
Delaney, Jeremy S
Cuadros, Javier
Africa, Tanzania; Age model; HAND; Illite; Olduvai-Paleolake; Sample ID; Sampling by hand; Smectite; δ18O, illite-smectite
Most clay minerals in sedimentary environments have traditionally been considered to be of detrital origin, but under certain conditions, authigenic clay minerals can form at low temperature through the transformation of precursor clays or as direct precipitates from lake-water. Such clay minerals can hold important information about the prevailing climatic conditions during the time of deposition. We present the first quantitative reconstruction of salinity in paleolake Olduvai based on the oxygen-isotope composition of authigenic clay minerals. We provide a framework illustrating that the isotopic signature of authigenic lacustrine clay minerals is related to the isotopic composition of paleo-waters, and hence to paleosalinity. This new paleosalinity proxy shows that the early Pleistocene East African monsoon was driven by combinations of precession and obliquity forcing, and subsequent changes in tropical SSTs. Such quantitative lacustrine paleosalinity estimates provides a new direction of research for modeling ecosystem change based on an ecologically relevant parameter.
title Relative proportions of smectite and illite, and illite-smectite oxygen-isotope compositions (δ18OI-S) of 39 mudstone samples collected from a lacustrian section at Paleolake Olduvai
topic Africa, Tanzania; Age model; HAND; Illite; Olduvai-Paleolake; Sample ID; Sampling by hand; Smectite; δ18O, illite-smectite
url https://doi.org/10.1594/PANGAEA.910866