@article{DeinoDommainKelleretal.2019,
  author    = {Deino, A. L. and Dommain, Ren{\´e} and Keller, C. B. and Potts, R. and Behrensmeyer, A. K. and Beverly, E. J. and King, J. and Heil, C. W. and Stockhecke, M. and Brown, E. T. and Moerman, J. and deMenocal, P. and Deocampo, D. and Garcin, Yannick and Levin, N. E. and Lupien, R. and Owen, R. B. and Rabideaux, N. and Russell, J. M. and Scott, J. and Riedl, S. and Brady, K. and Bright, J. and Clark, J. B. and Cohen, A. and Faith, J. T. and Noren, A. and Muiruri, V. and Renaut, R. and Rucina, S. and Uno, K.},
  title     = {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},
  series = {Quaternary science reviews : the international multidisciplinary research and review journal},
  volume    = {215},
  journal   = {Quaternary science reviews : the international multidisciplinary research and review journal},
  publisher = {Elsevier},
  address   = {Oxford},
  organization    = {Olorgesailie Drilling Project Sci},
  issn      = {0277-3791},
  doi       = {10.1016/j.quascirev.2019.05.009},
  pages     = {213 -- 231},
  year      = {2019},
  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 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.},
  language  = {en}
}
@article{DeinoSierGarelloetal.2019,
  author    = {Deino, Alan L. and Sier, Mark Jan and Garello, Dominique and Keller, B. and Kingston, John and Scott, Jennifer J. and Dupont-Nivet, Guillaume and Cohen, Andrew},
  title     = {Chronostratigraphy of the Baringo-Tugen-Barsemoi (HSPDP-BTB13-1A) core-Ar-40/Ar-39 dating, magnetostratigraphy, tephrostratigraphy, sequence stratigraphy and Bayesian age modeling},
  series = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences},
  volume    = {532},
  journal   = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0031-0182},
  doi       = {10.1016/j.palaeo.2019.109258},
  pages     = {16},
  year      = {2019},
  abstract  = {The Baringo-Tugen-Barsemoi 2013 drillcore (BTB13), acquired as part of the Hominin Sites and Paleolakes Drilling Project, recovered 228 m of fluviolacustrine sedimentary rocks and tuffs spanning a similar to 3.29-2.56 Ma interval of the highly fossiliferous and hominin-bearing Chemeron Formation, Tugen Hills, Kenya. Here we present a Bayesian stratigraphic age model for the core employing chronostratigraphic control points derived from Ar-40/Ar-39 dating of tuffs from core and outcrop, Ar-40/Ar-39 age calibration of related outcrop diatomaceous units, and core magnetostratigraphy. The age model reveals three main intervals with distinct sediment accumulation rates: an early rapid phase from 3.2 to 2.9 Ma; a relatively slow phase from 2.9 to 2.7 Ma; and the highest rate of accumulation from 2.7 to 2.6 Ma. The intervals of rapid accumulation correspond to periods of high Earth orbital eccentricity, whereas the slow accumulation interval corresponds to low eccentricity at 2.9-2.7 Ma, suggesting that astronomically mediated climate processes may be responsible for the observed changes in sediment accumulation rate. Lacustrine transgression-regression events, as delineated using sequence stratigraphy, dominantly operate on precession scale, particularly within the high eccentricity periods. A set of erosively based fluvial conglomerates correspond to the 2.9-2.7 Ma interval, which could be related to either the depositional response to low eccentricity or to the development of unconformities due to local tectonic activity. Age calibration of core magnetic susceptibility and gamma density logs indicates a close temporal correspondence between a shift from high- to low-frequency signal variability at similar to 3 Ma, approximately coincident the end of the mid-Piacenzian Warm Period, and the beginning of the cooling of world climate leading to the initiation of Northern Hemispheric glaciation c. 2.7 Ma. BTB13 and the Baringo Basin records may thus provide evidence of a connection between high-latitude glaciation and equatorial terrestrial climate toward the end of the Pliocene.},
  language  = {en}
}
@article{LevAlmogiLabinMischkeetal.2014,
  author    = {Lev, L. and Almogi-Labin, Ahuva and Mischke, Steffen and Ito, E. and Ben-Avraham, Zvi and Stein, M.},
  title     = {Paleohydrology of Lake Kinneret during the Heinrich event H2},
  series = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences},
  volume    = {396},
  journal   = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0031-0182},
  doi       = {10.1016/j.palaeo.2014.01.005},
  pages     = {183 -- 193},
  year      = {2014},
  abstract  = {During the last glacial period lake Kinneret (the Sea of Galilee) fluctuated between high and low water levels reflecting the hydrological conditions of the lake watershed. Here, we focus on the hydrology of the lake after its retreat from the last glacial MIS2 (similar to 27-25 ka BP) highest stand of similar to 170 m below mean sea level (m bsl) to the low stand of similar to 214 m bsl at similar to 24-21 ka BP. The limnological-hydrological history of this time interval is recovered from trench and borehole that were dug and drilled in the southwestern shore of the lake at Ohalo-II archeological site. Cyprideis torosa (Ostracoda) recovered from the trench yielded elemental, Sr-87/Sr-86 and delta O-18 isotope data that provide information on the shore environment during the low stand period. The Sr-87/Sr-86 and Sr/Ca ratios in the ostracods, varying between similar to 0.70789 and similar to 0.70815 and 0.0017 and 0.0030, respectively indicate contributions of waters from the last glacial lake and regional runoff. The increase in the Sr-87/Sr-86 ratios reflects the decreasing effect of the last glacial Lake Kinneret waters and enhanced contribution of local runoff that washed down dried mountain soils that were previously developed during the wet and vegetated glacial. The lake retreat at similar to 24 ka BP coincided with the Heinrich event H2 at the northern Atlantic. H2 was expressed by severe aridity in Lake Kinneret-Dead Sea watershed. The limnological-hydrological change at post H2 was accompanied by 2\% decrease in the delta O-18 value from -2\% to -4\% reflecting the change in the composition of the east Mediterranean rain sources. The last glacial lake Sr-87/Sr-86 ratio is similar to the Tiberias Spa saline waters and distinctly different from the modern Lake Kinneret fresh waters: Sr-87/Sr-86 similar to 0.70785 compared to similar to 0.70760, respectively. This difference is explained by enhanced contribution of Ca-chloride brines with high Sr-87/Sr-86 values to the last glacial lake and reduced Jordan River contribution due to cold freezing conditions at its headwaters, while the modern Lake Kinneret is more affected by low Sr-87/Sr-86 freshwater from the Jordan watershed.},
  language  = {en}
}
@article{WangLiuMischkeetal.2012,
  author    = {Wang, Yongbo and Liu, Xingqi and Mischke, Steffen and Herzschuh, Ulrike},
  title     = {Environmental constraints on lake sediment mineral compositions from the Tibetan Plateau and implications for paleoenvironment reconstruction},
  series = {Journal of paleolimnolog},
  volume    = {47},
  journal   = {Journal of paleolimnolog},
  number    = {1},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {0921-2728},
  doi       = {10.1007/s10933-011-9549-2},
  pages     = {71 -- 85},
  year      = {2012},
  abstract  = {Inorganic minerals form a major component of lacustrine sediments and have the potential to reveal detailed information on previous climatic and hydrological conditions. The ability to extract such information however, has been restricted by a limited understanding of the relationships between minerals and the environment. In an attempt to fill in this gap in our knowledge, 146 surface sediment samples have been investigated from 146 lakes on the Tibetan Plateau. The mineral compositions derived from these samples by X-Ray Diffraction (XRD) were used to examine the relationships between mineral compositions and the environmental variables determined for each site. Statistical techniques including Multivariate regression trees (MRT) and Redundancy Analysis (RDA), based on the mineral spectra and environmental variables, reveal that the electrical conductivity (EC) and Mg/Ca ratios of lake water are the most important controls on the composition of endogenic minerals. No endogenic minerals precipitate under hyper-fresh water conditions (EC lower than 0.13 mS/cm), with calcite commonly forming in water with EC values above 0.13 mS/cm. Between EC values of 0.13 and 26 mS/cm the mineral composition of lake sediments can be explained in terms of variations in the Mg/Ca ratio: calcite dominates at Mg/Ca ratios of less than 33, whereas aragonite commonly forms when the ratio is greater than 33. Where EC values are between 26 and 39 mS/cm, monohydrocalcite precipitates together with calcite and aragonite; above 39 mS/cm, gypsum and halite commonly form. Information on the local geological strata indicates that allogenic (detrital) mineral compositions are primarily influenced by the bedrock compositions within the catchment area. By applying these relationships to the late glacial and Holocene mineral record from Chaka Salt Lake, five lake stages have been identified and their associated EC conditions inferred. The lake evolved from a freshwater lake during the late glacial (before 11.4 cal. ka BP) represented by the lowest EC values (< 0.13 mS/cm), to a saline lake with EC values slightly higher than 39 mS/cm during the early and mid Holocene (ca. 11.4-5.3 cal. ka BP), and finally to a salt lake (after 5.3 cal. ka BP). These results illustrate the utility of our mineral-environmental model for the quantitative reconstruction of past environmental conditions from lake sediment records.},
  language  = {en}
}
@article{OpitzWuennemannAichneretal.2012,
  author    = {Opitz, Stephan and W{\"u}nnemann, Bernd and Aichner, Bernhard and Dietze, Elisabeth and Hartmann, Kai and Herzschuh, Ulrike and IJmker, Janneke and Lehmkuhl, Frank and Li, Shijie and Mischke, Steffen and Plotzki, Anna and Stauch, Georg and Diekmann, Bernhard},
  title     = {Late Glacial and Holocene development of Lake Donggi Cona, north-eastern Tibetan Plateau, inferred from sedimentological analysis},
  series = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences},
  volume    = {337},
  journal   = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences},
  number    = {23},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0031-0182},
  doi       = {10.1016/j.palaeo.2012.04.013},
  pages     = {159 -- 176},
  year      = {2012},
  abstract  = {Sediments of Lake Donggi Cona on the northeastern Tibetan Plateau were studied to infer changes in the lacustrine depositional environment, related to climatic and non-climatic changes during the last 19 kyr. The lake today fills a 30x8 km big and 95 m deep tectonic basin, associated with the Kunlun Fault. The study was conducted on a sediment-core transect through the lake basin, in order to gain a complete picture of spatio-temporal environmental change. The recovered sediments are partly finely laminated and are composed of calcareous muds with variable amounts of carbonate micrite, organic matter, detrital silt and clay. On the basis of sedimentological, geochemical, and mineralogical data up to five lithological units (LU) can be distinguished that document distinct stages in the development of the lake system. The onset of the lowermost LU with lacustrine muds above basal sands indicates that lake level was at least 39 m below the present level and started to rise after 19 ka, possibly in response to regional deglaciation. At this time, the lacustrine environment was characterized by detrital sediment influx and the deposition of siliciclastic sediment. In two sediment cores, upward grain-size coarsening documents a lake-level fall after 13 cal ka BP, possibly associated with the late-glacial Younger Dryas stadial. From 11.5 to 4.3 cal ka BP, grain-size fining in sediment cores from the profundal coring sites and the onset of lacustrine deposition at a litoral core site (2 m water depth) in a recent marginal bay of Donggi Cona document lake-level rise during the early to mid-Holocene to at least modern level. In addition, high biological productivity and pronounced precipitation of carbonate micrites are consistent with warm and moist climate conditions related to an enhanced influence of summer monsoon. At 4.3 cal ka BP the lake system shifted from an aragonite- to a calcite-dominated system, indicating a change towards a fully open hydrological lake system. The younger clay-rich sediments are moreover non-laminated and lack any diagenetic sulphides, pointing to fully ventilated conditions, and the prevailing absence of lake stratification. This turning point in lake history could imply either a threshold response to insolation-forced climate cooling or a response to a non-climatic trigger, such as an erosional event or a tectonic pulse that induced a strong earthquake, which is difficult to decide from our data base.},
  language  = {en}
}
@phdthesis{Hultzsch2006,
  author    = {Hultzsch, Nadja},
  title     = {Lakustrine Sedimente als Archive des sp{\"a}tquart{\"a}ren Umweltwandels in der Amery-Oase, Ostantarktis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7980},
  school      = {Universit{\"a}t Potsdam},
  year      = {2006},
  abstract  = {Im Rahmen einer deutsch-australischen Forschungskooperation erfolgte im S{\"u}dsommer 2001/2002 eine Expedition in die Amery-Oase (70°50'S, 68°00'E), die im Einzugsgebiet des Lambert-Gletscher/Amery-Schelfeis-Systems, dem gr{\"o}ßten ostantarktischen Eis-Drainagesystem, liegt. Von deutscher Seite wurden im Zuge der Gel{\"a}ndekampagne erstmals lakustrine Sedimentsequenzen gewonnen, um die bislang wenig erforschte sp{\"a}tquart{\"a}re Klima- und Umweltgeschichte dieser rund 1800 km<sup>2 großen eisfreien Region zu rekonstruieren. Die drei untersuchten Glazialseen Beaver, Radok und Terrasovoje unterscheiden sich sowohl deutlich in ihrer Gr{\"o}ße, Bathymetrie und den hydrologischen Merkmalen sowie in ihren Sedimentabfolgen. Einen Schwerpunkte dieser Doktorarbeit bildet die Rekonstruktion der Sedimentationsprozesse und des Ablagerungsmilieus sowie Untersuchungen zur Herkunft des detritischen Sedimentmaterials in den Seebecken. Der methodische Ansatz verfolgt die Charakterisierung der klastischen Sedimentfazies an Hand lithologisch-granulometrischer Merkmale sowie mineralogisch-geochemischer Analysen der Sedimentherkunft. Ein weiterer Schwerpunkt ist die Rekonstruktion der holoz{\"a}nen biogen gesteuerten Ablagerungsbedingungen im Terrasovoje-See, die R{\"u}ckschl{\"u}sse auf den kurzfristigen postglazialen Klima- und Umweltwandel in der Amery-Oase gestattet. Dabei wurden mikrofazielle Untersuchungsmethoden und hochaufl{\"o}sende Elementscannermessungen angewandt. Die klastische Sedimentherkunft in den drei Seen unterscheidet sich r{\"a}umlich deutlich voneinander und spiegelt den komplexen geologischen Aufbau der Amery-Oase wider. Als Sedimentquellen konnten pr{\"a}kambrische Metamorphite, permotriassische Sedimentgesteine und terti{\"a}re Lockersedimente identifiziert werden. Die Varibilit{\"a}t der Herkunftssignale ist zeitlich weniger deutlich als r{\"a}umlich ausgepr{\"a}gt und deutet auf relativ konstante Liefergebiete in den einzelnen Seen hin. Das glaziolakustrine Ablagerungsmilieu der drei untersuchten Seen zeigt klare r{\"a}umliche und zeitliche Unterschiede. In allen drei Seen setzen sich die {\"a}lteren Sedimente aus grobk{\"o}rnigem, h{\"a}ufig diamiktischem Material zusammen, w{\"a}hrend die j{\"u}ngeren Sedimente aus feink{\"o}rnigen Laminiten bestehen. Die lithofazielle Zweiteilung in den Sedimentabfolgen deutet auf einen R{\"u}ckzug der Gletscher und/oder einen Anstieg der Wassertiefen im {\"U}bergang von den grobk{\"o}rnigen zu den feink{\"o}rnigen Ablagerungseinheiten hin. Die oberen feink{\"o}rnigen Kernabschnitte spiegeln in allen drei Seen die postglaziale lakustrine Sedimentation wider. Im Beaver-See wird die postglaziale Fazies durch laminierte klastische Stillwassersedimente repr{\"a}sentiert, im Radok-See durch Turbiditsequenzen und im Terrasovoje-See durch Algenlaminite. Abgesehen vom Terrasovoje-See ist die zeitliche Einordnung der Fazieswechsel auf Grund mangelnder Altersinformationen schwer erfassbar. Im Terrasovoje-See setzte die postglaziale Sedimentation um rund 12,4 cal. ka ein. Somit weisen die darunterliegenden glazigenen Klastika mindestens ein sp{\"a}tpleistoz{\"a}nes Alter auf. Die sedimentologischen Eigenschaften, {\"A}nderungen der Sedimentationsraten und organogene Zusammensetzung der postglazialen Biogenlaminite des Terrasovoje-Sees deuten auf Variationen der pal{\"a}olimnologischen Bedingungen hinsichtlich Eisbedeckung, biologischer Produktivit{\"a}t, Wasserstand, Redoxbedingungen und Salinit{\"a}t hin, die mit regionalen holoz{\"a}nen Klima{\"a}nderungen in Verbindung gebracht werden k{\"o}nnen. Weitere Anhaltspunkte ergeben sich aus der Zusammensetzung und den M{\"a}chtigkeitsvariationen der Laminae, die generell aus Wechsellagerungen von Cyanobakterienmatten mit feinklastischen Lagen bestehen. Lagenz{\"a}hlungen der Laminae belegen {\"A}nderungen des Ablagerungsmilieus auf subdekadischen Zeitskalen, wobei zeitweilige j{\"a}hrliche Signale nicht ausgeschlossen werden k{\"o}nnen. Unter Ber{\"u}cksichtigung aller faziellen Indikatoren l{\"a}sst sich aus der Sedimentabfolge des Terrasovoje-Sees ein fr{\"u}hholoz{\"a}nes Klimaoptimum zwischen 9 und 7 cal. ka sowie weitere W{\"a}rmephasen zwischen 3,2 und 2,3 cal. ka sowie 1,5 und 1,0 cal. ka ableiten. Im Vergleich mit Eiskernarchiven und anderen Seesedimentabfolgen aus ostantarktischen Oasen zeigt sich, dass das Auftreten postglazialer Warmphasen nicht allenorts einem allgemein g{\"u}ltigen r{\"a}umlich-zeitlichen Muster folgt. Die Ursachen hierf{\"u}r liegen vermutlich in den lokalen geographischen Gegebenheiten. Es l{\"a}sst sich daraus schliessen, dass die bisher vorliegenden Klimarekonstruktionen eher das Lokalklima an einem Untersuchungsstandort als das Großklima der Ostantarktis reflektieren. Daraus ergibt sich die Notwendigkeit weiterer Untersuchungen von antarktischen Klimaarchiven und Untersuchungsstandorten, um {\"o}rtliche von {\"u}berregionalen Klimasignalen besser unterscheiden zu k{\"o}nnen.},
  subject      = {Antarktis},
  language  = {de}
}