TY  - GEN
A1  - Cohen, Abby
A1  - Campisano, Christopher
A1  - Arrowsmith, J. Ramon
A1  - Asrat, Asfawossen
A1  - Behrensmeyer, A. K.
A1  - Deino, A.
A1  - Feibel, C.
A1  - Hill, A.
A1  - Johnson, R.
A1  - Kingston, J.
A1  - Lamb, Henry F.
A1  - Lowenstein, T.
A1  - Noren, A.
A1  - Olago, D.
A1  - Owen, Richard Bernhart
A1  - Potts, R.
A1  - Reed, Kate
A1  - Renaut, R.
A1  - Schäbitz, F.
A1  - Tiercelin, J.-J.
A1  - Trauth, Martin  H.
A1  - Wynn, J.
A1  - Ivory, S.
A1  - Brady, K.
A1  - O’Grady, R.
A1  - Rodysill, J.
A1  - Githiri, J.
A1  - Russell, Joellen
A1  - Foerster, Verena
A1  - Dommain, René
A1  - Rucina, J. S.
A1  - Deocampo, D.
A1  - Russell, J.
A1  - Billingsley, A.
A1  - Beck, C.
A1  - Dorenbeck, G.
A1  - Dullo, L.
A1  - Feary, D.
A1  - Garello, D.
A1  - Gromig, R.
A1  - Johnson, T.
A1  - Junginger, Annett
A1  - Karanja, M.
A1  - Kimburi, E.
A1  - Mbuthia, A.
A1  - McCartney, Tannis
A1  - McNulty, E.
A1  - Muiruri, V.
A1  - Nambiro, E.
A1  - Negash, E. W.
A1  - Njagi, D.
A1  - Wilson, J. N.
A1  - Rabideaux, N.
A1  - Raub, Timothy
A1  - Sier, Mark Jan
A1  - Smith, P.
A1  - Urban, J.
A1  - Warren, M.
A1  - Yadeta, M.
A1  - Yost, Chad
A1  - Zinaye, B.
T1  - The Hominin Sites and Paleolakes Drilling Project
BT  - inferring the environmental context of human evolution from eastern African rift lake deposits
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 611 
KW  - Turkana-Basin
KW  - Adar formation
KW  - climate-change
KW  - olorgesailie formation
KW  - Southern Ethiopia
KW  - global climate
KW  - Kenya Rift
KW  - Pleistocene
KW  - variability
KW  - patterns
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-412498
IS  - 611
ER  - 
TY  - JOUR
A1  - Deino, A. L.
A1  - Dommain, René
A1  - Keller, C. B.
A1  - Potts, R.
A1  - Behrensmeyer, A. K.
A1  - Beverly, E. J.
A1  - King, J.
A1  - Heil, C. W.
A1  - Stockhecke, M.
A1  - Brown, E. T.
A1  - Moerman, J.
A1  - deMenocal, P.
A1  - Deocampo, D.
A1  - Garcin, Yannick
A1  - Levin, N. E.
A1  - Lupien, R.
A1  - Owen, R. B.
A1  - Rabideaux, N.
A1  - Russell, J. M.
A1  - Scott, J.
A1  - Riedl, S.
A1  - Brady, K.
A1  - Bright, J.
A1  - Clark, J. B.
A1  - Cohen, A.
A1  - Faith, J. T.
A1  - Noren, A.
A1  - Muiruri, V.
A1  - Renaut, R.
A1  - Rucina, S.
A1  - Uno, K.
T1  - 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
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
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 OL012-1A 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 OL012-1A. Firstly, chronostratigraphic control points for the core were established based on 4 Ar/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, nonlinear 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 inter connectivity of the Koora Basin to adjacent areas and sources of volcanism. (C) 2019 Elsevier Ltd. All rights reserved.
KW  - Pleistocene
KW  - Paleolimnology
KW  - East Africa
KW  - Sedimentology
KW  - Radiogenic isotopes
KW  - Bayesian modeling
KW  - paleosol
KW  - Tephrostratigraphy
KW  - Magnetostratigraphy
KW  - Kenya Rift
Y1  - 2019
U6  - https://doi.org/10.1016/j.quascirev.2019.05.009
SN  - 0277-3791
VL  - 215
SP  - 213
EP  - 231
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Richter, Maximilian
A1  - Brune, Sascha
A1  - Riedl, Simon
A1  - Glerum, Anne
A1  - Neuharth, Derek
A1  - Strecker, Manfred
T1  - Controls on asymmetric rift dynamics
BT  - Numerical modeling of strain localization and fault evolution in the Kenya Rift
JF  - Tectonics / American Geophysical Union, AGU ; European Geophysical Society, EGS
N2  - Complex, time-dependent, and asymmetric rift geometries are observed throughout the East African Rift System (EARS) and are well documented, for instance, in the Kenya Rift. To unravel asymmetric rifting processes in this region, we conduct 2D geodynamic models. We use the finite element software ASPECT employing visco-plastic rheologies, mesh-refinement, distributed random noise seeding, and a free surface. In contrast to many previous numerical modeling studies that aimed at understanding final rifted margin symmetry, we explicitly focus on initial rifting stages to assess geodynamic controls on strain localization and fault evolution. We thereby link to geological and geophysical observations from the Southern and Central Kenya Rift. Our models suggest a three-stage early rift evolution that dynamically bridges previously inferred fault-configuration phases of the eastern EARS branch: (1) accommodation of initial strain localization by a single border fault and flexure of the hanging-wall crust, (2) faulting in the hanging-wall and increasing upper-crustal faulting in the rift-basin center, and (3) loss of pronounced early stage asymmetry prior to basinward localization of deformation. This evolution may provide a template for understanding early extensional faulting in other branches of the East African Rift and in asymmetric rifts worldwide. By modifying the initial random noise distribution that approximates small-scale tectonic inheritance, we show that a spectrum of first-order fault configurations with variable symmetry can be produced in models with an otherwise identical setup. This approach sheds new light on along-strike rift variability controls in active asymmetric rifts and proximal rifted margins.
KW  - asymmetric rifting
KW  - rift variability
KW  - numerical model
KW  - structural
KW  - inheritance
KW  - Kenya Rift
Y1  - 2021
U6  - https://doi.org/10.1029/2020TC006553
SN  - 0278-7407
SN  - 1944-9194
VL  - 40
IS  - 5
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Riedl, Simon
A1  - Melnick, Daniel
A1  - Njue, Lucy
A1  - Sudo, Masafumi
A1  - Strecker, Manfred
T1  - Mid-Pleistocene to recent crustal extension in the inner graben of the Northern Kenya Rift
JF  - Geochemistry, geophysics, geosystems
N2  - Magmatic continental rifts often constitute nascent plate boundaries, yet long-term extension rates and transient rate changes associated with these early stages of continental breakup remain difficult to determine. Here, we derive a time-averaged minimum extension rate for the inner graben of the Northern Kenya Rift (NKR) of the East African Rift System for the last 0.5 m.y. We use the TanDEM-X science digital elevation model to evaluate fault-scarp geometries and determine fault throws across the volcano-tectonic axis of the inner graben of the NKR. Along rift-perpendicular profiles, amounts of cumulative extension are determined, and by integrating four new Ar-40/Ar-39 radiometric dates for the Silali volcano into the existing geochronology of the faulted volcanic units, time-averaged extension rates are calculated. This study reveals that in the inner graben of the NKR, the long-term extension rate based on mid-Pleistocene to recent brittle deformation has minimum values of 1.0-1.6 mm yr(-1), locally with values up to 2.0 mm yr(-1). A comparison with the decadal, geodetically determined extension rate reveals that at least 65% of the extension must be accommodated within a narrow, 20-km-wide zone of the inner rift. In light of virtually inactive border faults of the NKR, we show that extension is focused in the region of the active volcano-tectonic axis in the inner graben, thus highlighting the maturing of continental rifting in the NKR.
KW  - extensional tectonics
KW  - Kenya Rift
KW  - TanDEM-X DEM
KW  - DEM analysis
KW  - geochronology
KW  - normal faults
Y1  - 2022
U6  - https://doi.org/10.1029/2021GC010123
SN  - 1525-2027
VL  - 23
IS  - 3
PB  - American Geophysical Union
CY  - Washington
ER  -