Abstract
The Olorgesailie Drilling Project and the related Hominin Sites and Paleolakes Drilling Project in East Africa were initiated to test hypotheses and models linking environmental change to hominin evolution by drilling lake basin sediments adjacent to important archeological and paleoanthropological sites. Drill core OLO12-1A recovered 139 m of sedimentary and volcaniclastic strata from the Koora paleolake basin, southern Kenya Rift, providing the opportunity to compare paleoenvironmental influences over the past million years with the parallel record exposed at the nearby Olorgesailie archeological site. To refine our ability to link core-to-outcrop paleoenvironmental records, we institute here a methodological framework for deriving a robust age model for the complex lithostratigraphy of OLO12-1A. Firstly, chronostratigraphic control points for the core were established based on 40Ar/39Ar ages from intercalated tephra deposits and a basal trachyte flow, as well as the stratigraphic position of the Brunhes-Matuyama geomagnetic reversal. This dataset was combined with the position and duration of paleosols, and analyzed using a new Bayesian algorithm for high-resolution age-depth modeling of hiatus-bearing stratigraphic sections. This model addresses three important aspects relevant to highly dynamic, non-linear depositional environments: 1)correcting for variable rates of deposition, 2)accommodating hiatuses, and 3)quantifying realistic age uncertainty with centimetric resolution. Our method is applicable to typical depositional systems in extensional rifts as well as to drill cores from other dynamic terrestrial or aquatic environments. We use the core age model and lithostratigraphy to examine the interconnectivity of the Koora Basin to adjacent areas and sources of volcanism.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 213-231 |
| Number of pages | 19 |
| Journal | Quaternary Science Reviews |
| Volume | 215 |
| DOIs | |
| State | Published - Jul 1 2019 |
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Keywords
- Bayesian modeling
- East Africa
- Kenya Rift
- Magnetostratigraphy
- Paleolimnology
- Pleistocene
- Radiogenic isotopes
- Sedimentology
- Tephrostratigraphy
- paleosol
Cite this
Chronostratigraphic model of a high-resolution drill core record of the past million years from the Koora Basin, south Kenya Rift : Overcoming the difficulties of variable sedimentation rate and hiatuses. / the Olorgesailie Drilling Project Scientific Team.
In: Quaternary Science Reviews, Vol. 215, 01.07.2019, p. 213-231.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Chronostratigraphic model of a high-resolution drill core record of the past million years from the Koora Basin, south Kenya Rift
T2 - Overcoming the difficulties of variable sedimentation rate and hiatuses
AU - the Olorgesailie Drilling Project Scientific Team
AU - Deino, A. L.
AU - Dommain, R.
AU - Keller, C. B.
AU - Potts, R.
AU - Behrensmeyer, A. K.
AU - Beverly, E. J.
AU - King, J.
AU - Heil, C. W.
AU - Stockhecke, M.
AU - Brown, Erik T
AU - Moerman, J.
AU - deMenocal, P.
PY - 2019/7/1
Y1 - 2019/7/1
N2 - The Olorgesailie Drilling Project and the related Hominin Sites and Paleolakes Drilling Project in East Africa were initiated to test hypotheses and models linking environmental change to hominin evolution by drilling lake basin sediments adjacent to important archeological and paleoanthropological sites. Drill core OLO12-1A recovered 139 m of sedimentary and volcaniclastic strata from the Koora paleolake basin, southern Kenya Rift, providing the opportunity to compare paleoenvironmental influences over the past million years with the parallel record exposed at the nearby Olorgesailie archeological site. To refine our ability to link core-to-outcrop paleoenvironmental records, we institute here a methodological framework for deriving a robust age model for the complex lithostratigraphy of OLO12-1A. Firstly, chronostratigraphic control points for the core were established based on 40Ar/39Ar ages from intercalated tephra deposits and a basal trachyte flow, as well as the stratigraphic position of the Brunhes-Matuyama geomagnetic reversal. This dataset was combined with the position and duration of paleosols, and analyzed using a new Bayesian algorithm for high-resolution age-depth modeling of hiatus-bearing stratigraphic sections. This model addresses three important aspects relevant to highly dynamic, non-linear depositional environments: 1)correcting for variable rates of deposition, 2)accommodating hiatuses, and 3)quantifying realistic age uncertainty with centimetric resolution. Our method is applicable to typical depositional systems in extensional rifts as well as to drill cores from other dynamic terrestrial or aquatic environments. We use the core age model and lithostratigraphy to examine the interconnectivity of the Koora Basin to adjacent areas and sources of volcanism.
AB - The Olorgesailie Drilling Project and the related Hominin Sites and Paleolakes Drilling Project in East Africa were initiated to test hypotheses and models linking environmental change to hominin evolution by drilling lake basin sediments adjacent to important archeological and paleoanthropological sites. Drill core OLO12-1A recovered 139 m of sedimentary and volcaniclastic strata from the Koora paleolake basin, southern Kenya Rift, providing the opportunity to compare paleoenvironmental influences over the past million years with the parallel record exposed at the nearby Olorgesailie archeological site. To refine our ability to link core-to-outcrop paleoenvironmental records, we institute here a methodological framework for deriving a robust age model for the complex lithostratigraphy of OLO12-1A. Firstly, chronostratigraphic control points for the core were established based on 40Ar/39Ar ages from intercalated tephra deposits and a basal trachyte flow, as well as the stratigraphic position of the Brunhes-Matuyama geomagnetic reversal. This dataset was combined with the position and duration of paleosols, and analyzed using a new Bayesian algorithm for high-resolution age-depth modeling of hiatus-bearing stratigraphic sections. This model addresses three important aspects relevant to highly dynamic, non-linear depositional environments: 1)correcting for variable rates of deposition, 2)accommodating hiatuses, and 3)quantifying realistic age uncertainty with centimetric resolution. Our method is applicable to typical depositional systems in extensional rifts as well as to drill cores from other dynamic terrestrial or aquatic environments. We use the core age model and lithostratigraphy to examine the interconnectivity of the Koora Basin to adjacent areas and sources of volcanism.
KW - Bayesian modeling
KW - East Africa
KW - Kenya Rift
KW - Magnetostratigraphy
KW - Paleolimnology
KW - Pleistocene
KW - Radiogenic isotopes
KW - Sedimentology
KW - Tephrostratigraphy
KW - paleosol
UR - http://www.scopus.com/inward/record.url?scp=85067949023&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85067949023&partnerID=8YFLogxK
U2 - 10.1016/j.quascirev.2019.05.009
DO - 10.1016/j.quascirev.2019.05.009
M3 - Article
VL - 215
SP - 213
EP - 231
JO - Quaternary Science Reviews
JF - Quaternary Science Reviews
SN - 0277-3791
ER -