@article{MischkeAlmogiLabinAlSaqaratetal.2014, author = {Mischke, Steffen and Almogi-Labin, Ahuva and Al-Saqarat, Bety and Rosenfeld, Arik and Elyashiv, Hadar and Boomer, Ian and Stein, Mordechai and Lev, Lilach and Ito, Emi}, title = {An expanded ostracod-based conductivity transfer function for climate reconstruction in the Levant}, series = {Quaternary science reviews : the international multidisciplinary research and review journal}, volume = {93}, journal = {Quaternary science reviews : the international multidisciplinary research and review journal}, publisher = {Elsevier}, address = {Oxford}, issn = {0277-3791}, doi = {10.1016/j.quascirev.2014.04.004}, pages = {91 -- 105}, year = {2014}, abstract = {We present the first modern calibration dataset linking ostracod assemblage composition to water chemistry, and other site-specific variables, in the hydrologically and geopolitically sensitive southern Levant region. A total of 42 ostracod taxa were recorded from the 178 sampled sites in Israel and Jordan. Ilyocypris spp., Heterocypris salina and Cypridopsis vidua are the most abundant taxa. Species strictly confined to freshwater conditions are Prionocypris zenkeri, Gomphocythere ortali and Prionocypris olivaceus. In contrast, H. sauna, Bradleytriebella lineata and Cyprideis torosa show high frequencies in brackish waters (waters with higher conductivity). Humphcypris subterranea, G. ortali, P. olivaceus and Cypridopsis elongata apparently prefer flowing waters. Specific conductivity optima and tolerance ranges were calculated for the recorded ostracod species and may be used for the palaeoenvironmental assessment of fossil ostracod assemblages. In addition, a transfer-function for quantitative specific conductivity estimation based on 141 samples was established with weighted averaging partial least squares regression (WA-PLS). The resulting coefficient of determination r(2) between observed and predicted conductivity values (0.72) and the root-mean-square error of prediction (RMSEP) in \% gradient length (13.1) indicate that conductivity may be reliably estimated from ostracod assemblage data. The transfer function was first applied to last glacial ostracod assemblage data from an archaeological trench in the Sea of Galilee (northern Israel). Relatively large conductivity fluctuations between ca 1 and 7 mS cm(-1) were inferred for the period 24-20 cal ka BP. In addition, four episodes of freshwater influx near the site of the trench were identified from the presence of shells of freshwater and stream-dwelling species intermingled with very abundant shells of Cyprideis torosa. The results of our study allow a better use of Quaternary ostracods from the Levant as palaeoenvironmental indicators of water-body types and past conductivity levels and will contribute to a better understanding of Quaternary environmental and climate change in the Levant. (C) 2014 Elsevier Ltd. All rights reserved.}, language = {en} } @article{MischkeAshkenaziAlmogiLabinetal.2014, author = {Mischke, Steffen and Ashkenazi, Shoshana and Almogi-Labin, Ahuva and Goren-Inbar, Naama}, title = {Ostracod evidence for the Acheulian environment of the ancient Hula Lake (Levant) during the early-mid Pleistocene transition}, series = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences}, volume = {412}, journal = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0031-0182}, doi = {10.1016/j.palaeo.2014.07.036}, pages = {148 -- 159}, year = {2014}, abstract = {Ostracod shells from the archaeological site Gesher BenotYa'aqov (GBY) in the upper Jordan River Valley (Israel) were investigated to improve the understanding of the environmental conditions of the Acheulian occupation site during the early-mid Pleistocene transition (0.78 Ma). The diverse ostracod assemblage consists of 28 species. The distribution of most of the recorded species in the region today shows that the hydrological conditions at the early-mid Pleistocene transition were not fundamentally different from the modern ones. However, the predominance of Candona neglecta shells in the GBY sequence probably indicates cooler climatic conditions than today. Shells of Candona angulata in the artefact-richer upper half of the sequence suggest a slight salinity increase in the ancient Hula Lake from pure freshwater to slightly oligohaline conditions. This shift probably resulted from wetter conditions and a more stable lake environment with increased residence time of the lake water and stronger influence of evaporation. Shells of the brackish water ostracod Cyprideis torosa and the slightly halophilic Heterocypris sauna and Plesiocypridopsis newtoni were recorded only rarely suggesting that the lake maintained an outlet through the entire period represented by the GBY sequence. Shells of Gomphocythere ortali in GBY cycles 1 and 2 imply that a permanent freshwater stream existed close to the site. Humphcypris subterranea shells in cycles 3-5 provide further evidence that a tributary entered the lake from the south in contrast to the modern setting with the north-south flowing Jordan River at GBY. Statistical analysis of the quantitative ostracod data from GBY identified a group of samples from layers containing more abundant stone artefacts and another group of samples from layers with scarce artefacts. Samples from layers containing more abundant artefacts have relatively high abundances of C. angulata, Darwinula stevensoni and Physocypria kraepelini shells and include rare shells of Ilyocypris hartmanni, Ilyocypris salebrosa, Heterocypris incongniens and Pseudocandona sp. 2 which do not occur in the other samples. The presence of P. kraepelini and H. incongruens shells in artefact-richer sediments possibly indicates poor bottom water oxygenation in the ancient Hula lake sometimes during the periods of Acheulian occupation. However, more detailed studies are required to assess whether lower dissolved oxygen levels in the lake resulted from a slight lake level rise and possibly higher nutrient flux to the lake during wetter conditions or whether hominins already impacted lake's nutrient status by butchering at its shore or by burning of near-shore vegetation. (c) 2014 Elsevier B.V. All rights reserved.}, language = {en} } @article{MischkeGinatAlSaqaratetal.2012, author = {Mischke, Steffen and Ginat, Hanan and Al-Saqarat, Bety and Almogi-Labin, Ahuva}, title = {Ostracods from water bodies in hyperarid Israel and Jordan as habitat and water chemistry indicators}, series = {Ecological indicators : integrating monitoring, assessment and management}, volume = {14}, journal = {Ecological indicators : integrating monitoring, assessment and management}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1470-160X}, doi = {10.1016/j.ecolind.2011.07.017}, pages = {87 -- 99}, year = {2012}, abstract = {The hyperarid region of Israel and Jordan covers a large area where numerous sites of Pleistocene lake sediments suggest that climate conditions were significantly wetter during the Pleistocene. This region experienced a significant increase in aridity in recent decades and the number of existing surface waters is diminishing rapidly. We studied ostracod shells from 49 pond and stream sites to determine the species distribution and to infer ecological preferences especially with respect to general differences in water movement, conductivity and ion composition. Twenty-two ostracod species were identified in total of which 12 taxa occur at three or more sites. Among the rarer species. Cyprinotus scholiosus was identified for the first time after two records from Plio- and Pleistocene sites in Yemen and Saudi Arabia. Further, Paracypretta amati was recorded and its ecological preferences discussed for the first time following the description of the species from its type locality in Sudan. Cypridopsis elongata is the only typical inhabitant of lotic habitats, strictly preferring freshwater conditions and waters with an alkalinity/Ca ratio around 1 and cations dominated by Ca(2+) and anions by HCO(3)(-). In contrast, Cyprideis torosa, Limnocythere inopinata and Heterocypris incongruens apparently prefer waters dominated by Na(+) associated with cations and Cl(-) associated with anions. Heterocypris salina and C. torosa occur over a wide conductivity (or salinity) range and in waters with alkalinity/Ca ratios around 1 and with significant alkalinity depletion. Humphcypris subterranea, Ilyocypris spp. and H. sauna are the only taxa which do not show any preference with respect to both the cation and anion dominance of the waters. The ecological preferences of the ostracod species from water bodies in the study area are discussed in detail and can be used for a qualitative assessment of the hydrodynamical and hydrochemical conditions of former water bodies in the presently hyperarid environment based on ostracod species composition analysis of Pleistocene aquatic sediments.}, 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} }