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I. Esteban R. M. Albert A. Eixea J. Zilhão V. Villaverde 《Archaeological and Anthropological Sciences》2017,9(2):265-278
Despite phytoliths having been used to understand past human use of plants and palaeoenvironment in Middle Paleolithic sites, little is known on this aspect in the well-documented central region of Mediterranean Iberia. This paper presents the first phytolith and mineralogical study conducted at Abrigo de la Quebrada (Chelva, Valencia). Forty-one samples were analyzed through phytoliths and Fourier transform infrared spectroscopy (FTIR) from different areas, stratigraphic levels, and archeological contexts (hearth, hearth-related, and non-hearth-related sediments) of the shelter. The results obtained point towards a different pattern of preservation in the site depending firstly on the stratigraphy and secondly on the area where the samples were collected. Postdepositional processes that may have chemically affected phytolith preservation are discussed. Grasses are the main plant component identified in all the samples while woody plants are scarce. The abundance of grasses in the non-hearth-related sediments might be related, at least partially, to the dispersion of ashes from hearths, as indicated by the FTIR results. The results are indicative of an occupation of the site during the spring-autumn season. At this time, the area would be dominated by a semi-open environment with supramediterranean vegetation. 相似文献
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Abstract Semi-arid landscapes are vulnerable to cultivation, overgrazing and climate variability, although it is difficult to identify the relative significance of these three factors. In the South African Karoo, the ‘desertification debate' seeks to explain a change to more shrubby vegetation in heavily grazed areas. We examine these issues in catchments where farm reservoirs provide sediment stores with 137Cs, 210Pb, geochemical and mineral magnetic signatures. Rainfall data and stocking numbers are reported and current erosion rates are estimated. Sediment accumulation in the reservoirs increases between 1935 and 1940, probably due to rises in the frequency of rainfall events of >25mm day. Significant increases in sedimentation rates (×8) occur during rain-fed wheat cultivation. In an uncultivated catchment, sediment yields remain relatively high and reflect increases in erosion from hillslopes, colluvial storage, and cultivated land sources. Gully systems have acted as transport routes rather than sediment sources over the last ~70 years. Badland erosion rates average ca. 50t ha?1 yr?1. At Ganora, their development in the 1920s strongly influences peak sedimentation between 1970 and 1980. Any delay between badland initiation and increased sediment yield appears to be a function of landscape connectivity. Recovery following disturbance is occurring slowly and is likely to take >100 years. De-stocking and better management systems are reducing erosion rates but may be offset by increases in rainfall intensity. 相似文献
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David I. Kertzer Darrett B. Rutman Sydel Silverman Andrejs Plakans 《Historical methods》2013,46(3):119-128
Abstract Mainstream geographical information systems techniques and packaged geographical information systems software are often inappropriate in historical contexts because they use geographical coordinates as a framework around which all other information is organized as “attribute data,” whereas in history locations are often the least certain part of our knowledge. A new and general architecture for documenting administrative units and organizing historical statistics is detailed, which prioritizes named entities and explicit semantic relationships such as “IsPartOf,” while holding coordinate data where available. This architecture is easily aligned with the recent development of geo-semantics by information scientists, meeting the formal requirements for a geo-spatial ontology, but was originally developed to enable the systematic computerization of traditional historical reference works, notably Frederick Youngs’ Guide to the Local Administrative Units of England. 相似文献