Negev Desert, Israel 350KYr Speleothem Stable Isotope Data Vaks, A.; Bar-Matthews, M.; Matthews, A.; Ayalon, A.; Frumkin, A. Vaks, A. Bar-Matthews, M. Matthews, A. Ayalon, A. Frumkin, A. hydrology earth science/paleoclimate/speleothems (sample identification,null,null,null,null,speleothems,null,null,C,null) earth science/paleoclimate/speleothems (delta 18O,calcium carbonate,null,per mil VPDB,null,speleothems,raw,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/speleothems (age,null,null,calendar kiloyear before present,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (delta 13C,calcium carbonate,null,per mil VPDB,null,speleothems,raw,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/speleothems earth science/paleoclimate/speleothems (Even-Sid-Ramon Caves>LATITUDE 30.6397>LONGITUDE 34.8099) Speleothems in arid and hyper-arid areas of Negev Desert, Israel, are used in paleoclimate reconstruction of northern margins of Saharan-Arabian Desert, focused on the following objectives: 1) precise U-Th dating of the timing of speleothem growth as an indicator of periods of humid climate, i.e. positive effective precipitation; 2) the origin of rainfall using the speleothem d18O and changes in spatial pattern of speleothem deposition and speleothem thickness along a north-south transect; 3) changes of vegetation cover based on speleothem d13C variations. During the last 350 ka major humid periods, referred to herein as Negev Humid Periods (NHP), occurred in the central and southern Negev Desert at 350-310 ka (NHP-4), 310-290 ka (NHP-3), 220-190 ka (NHP-2), and 142-109 ka (NHP-1). NHP-4, NHP-2 and NHP-1 are interglacial events, whereas NHP-3 is associated with a glacial period. During NHP-1, 2 and 3 the thickness and volume of the speleothems decrease from the north to the south, and in the most southern part of the region only a very thin flowstone layer formed during NHP-1, with no speleothem deposition occurring during NHP-2 and 3. These data imply that the Eastern Mediterranean Sea was the major source of the rainfall in northern and central Negev. More negative speleothem d18O values, relative to central parts of Israel (Soreq Cave) are attributed to Rayleigh distillation because of the increasing distance from the Mediterranean Sea. Speleothem deposition during the NHP-4 in the southern Negev was more intensive than in most of the central Negev, suggesting the prominence of the tropical rain source. Decrease in speleothem d13C during NHP events indicates growth of the vegetation cover. Nevertheless, the ranges of d13C values show that the vegetation remained semi-desert C4 type throughout the NHPs, with an additional significant carbon fraction coming from the host rock and the atmosphere. These observations, together with small thickness of the speleothem layers, favor that NHP events consisted of clusters of very short humid episodes interspersed with long droughts. NHP events were contemporaneous with climate periods with monsoon index of >=51 (cal/cm2 x day) and with the formation of sapropel layers in the Mediterranean Sea. Such simultaneous intensification of the monsoon and Atlantic-Mediterranean cyclones is probably related to the weakening of the high pressure cell above sub-tropical Atlantic Ocean, which enabled more rainfall to penetrate into the Saharan-Arabian Desert from the north and south. The contemporaneous occurrence of the NHP events and the increased monsoon rainfall could have opened migration corridors, creating climatic "windows of opportunity" for dispersals of hominids and animals out of the African continent. STUDY NOTES: Stable isotope (d18O and d13C) data from speleothems collected in 9 caves located in the Negev Desert, Israel. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Vaks, A. Investigator : Bar-Matthews, M. Investigator : Matthews, A. Investigator : Ayalon, A. Investigator : Frumkin, A. 2014-03-28 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/16402 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/israel/negev2010.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/israel/negev2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/israel/negev2010.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/israel/negev2010.xls English https://www.ncdc.noaa.gov/paleo/study/16402 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/israel/negev2010.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/israel/negev2010.xls Anton Vaks, Miryam Bar-Matthews, Alan Matthews, Avner Ayalon, Amos Frumkin2010Middle-Late Quaternary paleoclimate of northern margins of the Saharan-Arabian Desert: reconstruction from speleothems of Negev Desert, IsraelQuaternary Science Reviews2919-202647-266210.1016/j.quascirev.2010.06.014http://www.sciencedirect.com/science/article/pii/S0277379110002088 START YEAR: 338000 cal yr BP * END YEAR: 87300 cal yr BP 34.8099 30.6397 34.8099 30.6397