10 results
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2. Middle Eastern cloud distillation throughout the Holocene - Quantified using oxygen isotopes from speleothems and deep-sea cores.
- Author
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Lilach, Gonen and Yonaton, Goldsmith
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OXYGEN isotopes , *HOLOCENE Epoch , *DISTILLATION , *SPELEOTHEMS , *RAYLEIGH model , *HYDROLOGIC cycle - Abstract
The Middle East is considered a climate change "hot spot", where rainfall is expected to decline in the upcoming decades due to Global Warming. Reconstructing the long-term natural climate variability of this region is critical for understanding and contextualizing the current hydroclimate change and enables evaluating potential mechanisms that govern it. Oxygen isotopes (δ18O) from cave deposits are a high-resolution paleohydrological proxy, which previously has been interpreted as direct measures of rainfall amount. However, cave δ18O is controlled by a series of processes (e.g., evaporation, condensation and rainout history), and therefore, any paleohydrological interpretation using cave δ18O requires a thorough understanding and quantification of the full hydrological cycle. In this paper, we use a simple Rayleigh distillation model to assess the various processes that govern the isotopic composition of precipitation and quantify changes in cloud distillation during the Holocene throughout the Middle East. The results show that a west-east isotopic distillation gradient persisted throughout the Holocene in the Middle East. The early Holocene, coeval with Sapropel 1, was characterized by high distillation and a large west-east distillation gradient. At the end of sapropel 1, distillation dropped and the west-east gradient declined. The middle to late Holocene was characterized by a gradual increase in distillation, however the west-east distillation gradient continued declining. Similarity between the late Holocene distillation reconstruction and the Dead Sea lake-levels, strengthens the reliability of cloud distillation as a suitable hydroclimate proxy. These results show that periods of high distillation in the Levant occurred during both high and low summer insolation (early and late Holocene, respectively), and thus, were most likely the result of two different climatic mechanisms. Our distillation and distillation gradient records provide a new way to characterize the long-term natural climate variability in the Middle East and thus help resolve the climatic mechanisms governing this variability. • Holocene cloud distillation quantified using cave δ18O in Middle East Caves. • High distillation and high continentality characterized Middle East Early Holocene. • High distillation and low continentality characterized Middle East Late Holocene. • Jeita Cave distillation is similar to Dead Sea levels throughout the Holocene. • Different climate mechanisms operated during the Early and Late Holocene. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. The vegetation, climate, and fire history of a mountain steppe: A Holocene reconstruction from the South Caucasus, Shenkani, Armenia.
- Author
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Cromartie, Amy, Blanchet, Claire, Barhoumi, Chéïma, Messager, Erwan, Peyron, Odile, Ollivier, Vincent, Sabatier, Pierre, Etienne, David, Karakhanyan, Arkady, Khatchadourian, Lori, Smith, Adam T., Badalyan, Ruben, Perello, Bérengère, Lindsay, Ian, and Joannin, Sébastien
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HOLOCENE Epoch , *STEPPES , *GRASSLAND soils , *CLIMATOLOGY , *X-ray fluorescence , *GRASSLAND fires , *TREE-rings , *CHENOPODIACEAE - Abstract
Steppe and grassland ecosystems constitute important biomes that are influenced by multiple factors such as climate, human activity, and fire. Yet how these factors have influenced the plant composition of these biomes through time continues to be understudied. This paper investigates how these mechanisms have transformed the steppe landscape recorded at the mire site of Shenkani, Armenia. This highland site, located in the South Caucasus, has a long human history of permanent settlements near the core site starting at 5500 cal. BP. A variety of biological and geochemical proxies, including pollen, non-pollen palynomorphs, macro-charcoal, 14C age model, X-ray fluorescence, loss-of-ignition, magnetic susceptibility, and a quantitative climate reconstruction inferred from pollen, are utilized in this paper. We find that this area has remained a steppe with small stands of trees throughout the duration of the Holocene. Changes in steppe plant composition primarily occur between semi-desert steppes (Chenopodiaceae), grassland steppes (or Poaceae dominated meadow-steppes), and mixed steppes with forest patches. In this record, two phases of local grassland expansion occurred between 9500 and 7000 cal. BP and 2500–1000 cal. BP, which covaried with local fire events. These grassland steppes were sustained until tree encroachment led to a more mixed steppe landscape around 7000 cal. BP and again at 1000 cal. BP. Climate, primarily precipitation, is the main driver of this persistent steppe landscape and the plant compositional shifts within it. However, fire and human activities contributed to steppe maintenance. • A 10,240 year-old sequence from Shenkani, Armenia documents a persistent Holocene steppe. • Changes in steppe plant composition occur between semi-desert, grassland, and mixed steppes with forest patches. • Poaceae dominated grasslands covary with fires that limit tree and shrub encroachment. • The mid- to late Holocene transition is characterized by drops in Betula and declines in distant arboreal pollen. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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4. Climate, sea level and culture in the Southeastern Mediterranean 20–4 ky BP.
- Author
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Ronen, Avraham and Almagor, Gideon
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SEA level , *LAST Glacial Maximum , *COASTAL sediments , *COASTAL plains , *SOCIAL evolution , *COASTAL zone management , *SOCIAL factors - Abstract
In this paper sediments accumulated between 20 and 4 ky BP on the Israeli coastal plain and their cultural contents are described. Sediments carried by the Nile River into the Mediterranean are transported northward along the Levant coast. These sediments are intermittently windblown on land and together with their derivative sandy loams form the bulk of sediments on the coastal plain of Israel. The younger these sediments are further west they are located. The sand beds apparently accumulated during cold and dry periods and pedogenesis occurred during warm and humid periods. Cultural remains on the coastal plain are encountered only in the soils. Hence in periods of sand transport humans avoided the coastal plain. Between the Last Glacial Maximum (LGM, ca. 18–20 ky BP) and about 4 ky BP, global sea level rose from −130 to 0 m. The coastal sediments accumulated during that period are here correlated with both sea level and climatic factors. From the last glacial the living space was continuously shrinking under the encroaching sea and human communities were continuously driven landward. Cultural evolution since 20 ky ago includes major leaps such as the move from hunting-gathering nomads to permanent, year-round settlements, the birth of religion, domestication and food production. Climatic events seemingly played a minor role in these leaps. They were apparently initiated by social factors possibly stemming from environmental constraints – the progressive loss of living space. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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5. Lake Neor reveals how mountain vegetation responded to 7000 years of hydroclimate variability in northwestern Iran.
- Author
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Alinezhad, Khadijeh, Ramezani, Elias, Djamali, Morteza, Sharifi, Arash, Naqinezhad, Alireza, Aubert, Cyril, Gandouin, Emmanuel, and Pourmand, Ali
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MOUNTAIN plants ,VEGETATION dynamics ,ANALYTICAL geochemistry ,LAKES ,CLIMATE change ,TREE-rings ,CHENOPODIACEAE - Abstract
Palynological and geochemical analyses provide valuable information about modern and past climatic regimes and vegetation. The impact of climate and humans on past vegetation in the semi‐arid areas of northwestern Iran has received increased interest in the wake of warming temperatures in the Middle East. Palynological and down‐core XRF elemental abundances from a peat core from Lake Neor enabled a reconstruction of vegetational changes of the past 7000 years over the highlands of northwestern Iran. Periods of increased arboreal pollen (AP) types and high (Artemisia + Poaceae)/Chenopodiaceae ratios along with low titanium abundances, high percentages of total organic carbon, more negative δD values, and higher carbon accumulation rates suggest a relatively wet climate. These conditions have persisted during the periods 6700–6200, 5200–4450 and 3200–2200 cal a bp. The overall low AP values, substantial rise of Chenopodiaceae, high Ti abundances and low values of palaeo‐redox proxies, are all evidences of a drier climate, as has been reconstructed for the periods 6200–5200 and 4030–3150 cal a bp and the last 2200 years. An important feature of the last centuries is the increase of anthropogenic and pastoral indicator pollen types. Our results may provide basic data to predict future trends in vegetation dynamics under future climate change in western Asia. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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6. Developments in subsistence during the Early Bronze Age through the Iron Age in the southern and central Levant: Integration of faunal and botanical remains using multivariate statistics.
- Author
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Vermeersch, Shyama, Riehl, Simone, Starkovich, Britt M., and Kamlah, Jens
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IRON Age , *BRONZE Age , *SUBSISTENCE farming , *PLANT products , *ANIMAL products - Abstract
Subsistence patterns during the Early Bronze Age I through the Iron Age II (3600-586 BCE) are the topic of many archaeobotanical and zooarchaeological studies. The results of these two disciplines are usually published separately, depriving us of an all-encompassing view of subsistence and agriculture during this time period since people did not solely make use of animal or plant products. In this paper, our goal is to integrate faunal and botanical lines of evidence and study developments in subsistence using multivariate statistics. By analysing individual and integrated datasets of botanical and faunal remains, we aim to better understand the role of diverse variables, such as chronology, mean annual precipitation, and elevation within the composition of our datasets. We see chronological differences, a distinction between sites at higher (400–600 mm) and lower (200–400 mm) precipitation ranges and differences between sites at different elevations (0–100 m and 500–600 m). We also highlight methodological issues intrinsic to differences in genesis and quantification of archaeobotanical and zooarchaeological datasets. We conclude that to obtain a complete understanding of subsistence during the Bronze and Iron Age in the Southern Levant, archaeobotanists and zooarchaeologists need to work on integrating their data on a site-specific level. This will allow us to obtain a holistic understanding of subsistence and agricultural practices on both a site and regional level and allow us to develop a stronger framework for understanding social and political developments that occurred during these time periods. • Integration of archaeobotanical and zooarchaeological data is essential. • Multivariate statistics help understand past subsistence practices. • Bronze and Iron Age diet are determined by historical processes. • Early and Middle Bronze Age diet differs from Late Bronze Age and Iron Age diet. • Precipitation and elevation play a role in past subsistence. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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7. Holocene regional population dynamics and climatic trends in the Near East: A first comparison using archaeo-demographic proxies.
- Author
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Palmisano, Alessio, Lawrence, Dan, de Gruchy, Michelle W., Bevan, Andrew, and Shennan, Stephen
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POPULATION dynamics , *SPELEOTHEMS , *HOLOCENE Epoch , *LAKE sediments , *POPULATION , *CLIMATE change , *PALEOECOLOGY - Abstract
This paper illustrates long-term trends in human population and climate from the Late Pleistocene to the Late Holocene (14,000–2500 cal. yr. BP) in order to assess to what degree climate change impacted human societies in the Near East. It draws on a large corpus of archaeo-demographic data, including anthropogenic radiocarbon dates (n = 10,653) and archaeological site survey (n = 22,533), and 16 hydro-climatic records from cave speleothems and lake sediments. Where possible, inferred population dynamics and climatic trends have been made spatially congruent, and their relationships have been statistically tested. Demographic proxies and palaeoclimatic records have been compared for the greater Near East as a whole and for seven major geo-cultural regions (Anatolia, Arabia, Cyprus, Iran, Levant, Mesopotamia, and South Caucasus). This approach allows us to identify regionalised patterns in population and climate trends. The results suggest a clear relationship between population and climate in the Late Pleistocene and Early Holocene (14,000–8326 cal. yr. BP) with population increasing in concomitance with wetter climatic conditions. During the Middle Holocene (8326-4200 cal. yr. BP) there is an increased regionalisation of demographic patterns, followed by marked interregional contrasts in the Late Holocene (4200-2500 cal. yr. BP). We identify a decoupling of demographic and climatic trends from the Middle Holocene onwards, and relate this to the existence of more complex societies. These were less vulnerable to gradual climatic shifts due to their logistical infrastructure, social organisation and technological capacity. We also assess the impact of five Rapid Climate Changes (RCC) which occurred during the study period on population levels. Although all five RCC (the so-called 10.2 k, 9.2 k, 8.2 k, 4.2 k, and 3.2 k cal. yr. BP events) are visible to some degree in our palaeoclimatic and demographic proxies, there are marked regional variations in magnitude and duration. • Modelling regional demographic trends with archaeological proxies. • Long-term trends in human population and climate from the Late Pleistocene to the Late Holocene (14,000–2500 cal. yr. BP). • Regionalised patterns in population and climate trends. • Decoupling of demographic and climatic trends from the second half of the Middle Holocene (∼5500 cal. yr. BP). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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8. A subfossil spirostreptid millipede from SW Libya (Diplopoda, Spirostreptida, Spirostreptidae).
- Author
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Enghoff, Henrik and Van Neer, Wim
- Subjects
MILLIPEDES ,HOLOCENE Epoch ,INTERGLACIALS ,CONTINUOUS distributions ,RADIOCARBON dating - Abstract
Two fragments of millipedes, referred to the genus Archispirostreptus, are reported from an archaeological site in the Tadrart Acacus region of southwestern Libya. Radiocarbon dating of the specimens shows that one of them dates to between ca. 9100 and 8800 years ago, and the other one between 6400 and 6300 years ago (calibrated dates). The site lies far from known present-day occurrences of spirostreptid millipedes, and the Libyan subfossils probably, like other isolated occurrences of Archispirostreptus species in the Sahara and the Middle East, represent geographical relicts of a former, continuous distribution. The millipedes were probably able to survive at the Libyan site during the early and middle Holocene periods thanks to the more humid conditions, and may descend from animals that initially colonised the area during the even more humid, and longer, last interglacial period. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
9. Pleistocene to Recent scleractinian deep-water corals and coral facies in the Eastern Mediterranean.
- Author
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Taviani, M., Vertino, A., López Correa, M., Savini, A., De Mol, B., Remia, A., Montagna, P., Angeletti, L., Zibrowius, H., Alves, T., Salomidi, M., Ritt, B., and Henry, P.
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CORALS ,FOSSIL corals ,FACIES - Abstract
Recent investigations of the Eastern Mediterranean Sea carried out during the GECO cruise with RV Urania provided a substantial number of new cold-water coral (CWC) records, including branching and solitary scleractinian species. These new sites are located along steep escarpments and on topographic highs along the margins of Crete, Karpathos, and Rhodes. The majority of the corals represent fossil occurrences, predominantly Late Pleistocene assemblages. Our research documents that the Eastern Mediterranean Basin has been colonized by CWC at favorable times during the Last Glacial, in particular during the Younger Dryas. Schizocyathus fissilis is reported for the first time for the Mediterranean, while the finding of Ceratotrochus magnaghii represents the first record for the Eastern Mediterranean. Various coral facies occur on the southerly island slopes of Crete, Karpathos, and Rhodes, including hardgrounds and loose skeletal sediments. Hardgrounds occur on steep topographies between ca. 500 and 1,700 m, and can conveniently be subdivided as (1) Neopycnodonte- Desmophyllum framestone, (2) Desmophyllum- Caryophyllia framestone, (3) Madrepora- Lophelia rudstone, (4) Pelagic mudstone and wackestone, and (5) Siliciclastic-carbonate conglomerate and breccia. Unconsolidated skeletal sediments containing corals mainly occur on gentler topographic situations between ca. 140 and 600 m and can be subdivided as: (A) Lophelia- Madrepora rubble, (B) Dendrophyllia rubble, (C) Stenocyathus rubble, (D) Caryophyllia calveri rubble, and (E) fine-grained sediment with octocoral axes. Many of these facies types are also present in the western part of the Mediterranean and have fossil representatives from the Pleistocene to the Recent. Radiocarbon dating (AMS-C) reveals Younger Dryas ages between 12.4 and 12.0 ka cal BP for Lophelia pertusa and Madrepora oculata. Desmophyllum dianthus occurs during the Last Glacial Maximum (21.8 ka cal BP) and the Younger Dryas (11.7 ka cal BP), as well as during the Late Holocene and subrecent times (4.4-0.6 ka cal BP). Caryophyllia sarsiae occurs during the Late Glacial (15.5 ka cal BP), while Caryophyllia calveri occurs during the Early Preboreal (10.8 ka cal BP). The ages for the framework-constructing corals L. pertusa and M. oculata are coherent with their temporal predominance during the Younger Dryas in other parts of the Mediterranean. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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10. Mediterranean populations of the lesser white-toothed shrew ( Crocidura suaveolens group): an unexpected puzzle of Pleistocene survivors and prehistoric introductions.
- Author
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DUBEY, S., COSSON, J.-F., MAGNANOU, E., VOHRALÍK, V., BENDA, P., FRYNTA, D., HUTTERER, R., VOGEL, V., and VOGEL, P.
- Subjects
CYPRIOTS ,PLEISTOCENE stratigraphic geology ,CYTOCHROME b ,MITOCHONDRIA ,PHYLOGENY - Abstract
An earlier study revealed the strong phylogeographical structure of the lesser white-toothed shrew ( Crocidura suaveolens group) within the northern Palaearctic. Here, we aim to reconstruct the colonization history of Mediterranean islands and to clarify the biogeography and phylogeographical relationships of the poorly documented Middle East region with the northern Palaearctic. We performed analyses on 998-bp-long haplotypes of the mitochondrial cytochrome b gene of 143 samples collected around the Mediterranean basin, including islands and the Middle East. The analyses suggest that the Cypriot shrew belongs to the rare group of relict insular Pleistocene mammal taxa that have survived to the present day. In contrast, the Cretan, Corsican and Menorcan populations were independently introduced from the Middle East during the Holocene. The phylogeographical structure of this temperate Palaearctic species within the Middle East appears to be complex and rich in diversity, probably reflecting fragmentation of the area by numerous mountain chains. Four deeply divergent clades of the C. suaveolens group occur in the area, meaning that a hypothetical contact zone remains to be located in central western Iran. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
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