572 research outputs found
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The Legumes: The Earliest Domesticated Plants in the Near East?
Anthropolog
Potassium fertilization: paradox or K management dilemma?
In 2014, Khan et al. presented evidence that soil exchangeable K (Exch-K) increases over time without addition of potassium (K) to the soil despite the removal of K in crops on a soil rich in montmorillonite and illite. The authors term this behavior ‘The potassium paradox’. From their review of the literature, the authors also report a lack of crop response to potassium chloride (KCl) fertilization. Close evaluation of these findings reveals that their observations can be interpreted and predicted using current knowledge of K in soil chemistry and its uptake by plants, and there is no paradox in K behavior in the soil–plant system. There is also no evidence of a detrimental effect of KCl on crop yield or quality. Their conclusion that the widely used Exch-K soil test is inadequate for managing K fertilization is discussed and some possible modifications to improve its performance are included. We believe that measurement of Exch-K is an essential and valuable tool and its use should be continued, along with improvements in recommending K fertilizer application
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Structural Characterization of Charcoal Exposed to High and Low pH: Implications for 14C Sample Preparation and Charcoal Preservation
Chemical and structural similarities between poorly preserved charcoal and its contaminants, as well as low radiocarbon concentrations in old samples, complicate 14C age determinations. Here, we characterize 4 fossil charcoal samples from the late Middle Paleolithic and early Upper Paleolithic strata of Kebara Cave, Israel, with respect to the structural and chemical changes that occur when they are subjected to the acid-base-acid (ABA) treatment. Differential thermal analysis and TEM show that acid treatment disrupts the structure, whereas alkali treatment results in the reformation of molecular aggregates. The major changes are ascribed to the formation of salt bridges at high pH and the disruption of the graphite-like crystallites at low pH. Weight losses during the treatments are consistently greater for older samples, implying that they are less well preserved. Based on the changes observed in vitro due to pH fluctuations, various methods for removing contamination, as well as a mechanism for preferential preservation of charcoal in nature, are proposed.Anthropolog
The first Neanderthal remains from an open-air Middle Palaeolithic site in the Levant
The late Middle Palaeolithic (MP) settlement patterns in the Levant included the repeated use of caves and open landscape sites. The fossil record shows that two types of hominins occupied the region during this period - Neandertals and Homo sapiens. Until recently, diagnostic fossil remains were found only at cave sites. Because the two populations in this region left similar material cultural remains, it was impossible to attribute any open-air site to either species. In this study, we present newly discovered fossil remains from intact archaeological layers of the open-air site 'Ein Qashish, in northern Israel. The hominin remains represent three individuals: EQH1, a nondiagnostic skull fragment; EQH2, an upper right third molar (RM3); and EQH3, lower limb bones of a young Neandertal male. EQH2 and EQH3 constitute the first diagnostic anatomical remains of Neandertals at an open-air site in the Levant. The optically stimulated luminescence ages suggest that Neandertals repeatedly visited 'Ein Qashish between 70 and 60 ka. The discovery of Neandertals at open-air sites during the late MP reinforces the view that Neandertals were a resilient population in the Levant shortly before Upper Palaeolithic Homo sapiens populated the region
Virtual Sea-Drifting Experiments between the Island of Cyprus and the Surrounding Mainland in the Early Prehistoric Eastern Mediterranean
Seaborne movement underpins frontier research in prehistoric archaeology, including water-crossings in the context of human dispersals, and island colonisation. Yet, it also controls the degree of interaction between locations, which in turn is essential for investigating the properties of maritime networks. The onset of the Holocene (circa 12,000 years ago) is a critical period for understanding the origins of early visitors/inhabitants to the island of Cyprus in the Eastern Mediterranean in connection with the spread of Neolithic cultures in the region. The research undertaken in this work exemplifies the synergies between archaeology, physical sciences and geomatics, towards providing novel insights on the feasibility of drift-induced seaborne movement and the corresponding trip duration between Cyprus and coastal regions on the surrounding mainland. The overarching objective is to support archaeological inquiry regarding the possible origins of these visitors/inhabitants—Anatolia and/or the Levant being two suggested origins
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