265 research outputs found

    The Eneolithic/Bronze Age Transition at Tegole di Bovino (Apulia): Geoarchaeological Evidence of Climate Change and Land-Use Shift

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    Human communities at the transition between the Eneolithic period and the Bronze Age had to rapidly adapt to cultural and climatic changes, which influenced the whole Mediterranean. The exact dynamics involved in this crucial passage are still a matter of discussion. As newer studies have highlighted the key role of climatic fluctuations during this period, their relationship with the human occupation of the landscape are yet to be fully explored. We investigated the infilling of negative structures at the archaeological site of Tegole di Bovino (Apulia, Southern Italy) looking at evidence of the interaction between climate changes and human strategies. The archaeological sedimentary deposits, investigated though geoarchaeological and micromorphological techniques, show the presence of natural and anthropogenic infillings inside most structures. Both human intervention and/or natural events occurred in the last phases of occupation of the site and its subsequent abandonment. The transition to unfavorable climatic conditions in the same period was most likely involved in the abandonment of the site. The possible further impact of human communities on the landscape in that period, testified by multiple other archives, might have in turn had a role in the eventual change in land use

    Report on the INQUA-AEOMED field-trip workshop ‘Reconsidering Loess in Northern Italy’ (Po Plain, 1-3 July 2013)

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    This report presents the results of the field-trip workshop entitled \u2018Reconsidering Loess in Northern Italy\u2019 (Po Plain, 1-3 July 2013), organized in the framework of the AEOMED Project of the INQUA TERPRO Commission. The workshop focuses on presenting and discussing the sources and formation processes of the loess in the Po Plain area. The sedimentological, palaeopedological, palaeoclimatic and palaeoseismic aspects of five main loess sequences in the Po Plain (Val Sorda, Gajum, Monte Netto, Ghiardo, Boschi di Carrega) were presented and discussed in the field. The discussions carried out during three field days aim to map knowledge gaps and to define the next scientific goals in the field of loess research in the Po Plain in particular and in Italy in general

    Building on an oasis in Garamantian times: geoarchaeological investigation on mud architectural elements from the excavation of Fewet (Central Sahara, SW Libya)

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    The paper describes the micromorphological and mineralogical properties of earthen architectural elements from the excavation of the Garamantian compound of Fewet (Central Sahara, SW Libya), settled between the 2nd century BC and the 1st century AD, and compares this evidence with a set of samples from historical to modern context of Saharan and Sub-Saharan Africa. At Fewet, the production of mud bricks, plasters, and mortars employed in the building of the compound required raw materials available near the settlement. The earthen elements lack almost completely clay and organic temper, and their main components are quartz grains (sandy to silty) and a calcareous and slightly organic mud, available beside former springs. Only plaster and mortars show the addition (in limited quantity) of finely subdivided vegetal remains to the mixture. The technology for earthen elements used in Garamantian times resembles those today applied at many localities in Sub-Saharan Africa. Finally, our analyses showed that in the last millennia archaeological sediments underwent limited postdepositional weathering, mostly related to solute redistribution after occasional rainfalls. Today, the same process affects traditional mud brick buildings

    Variable fault tip propagation rates affected by near-surface lithology and implications for fault displacement hazard assessment

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    The fabric of reverse fault zones close to the surface is usually partitioned in between a narrow discrete rupture zone and a more distributed one, where folding is predominant. This makes quite challenging the adoption of proper setbacks in surface rupture hazard studies for critical facilities or microzoning. Some of the parameters controlling fault zone fabric are related to mechanics of near-surface geology (lithology, overburden thickness, cohesion and water content) whose interaction is complex and only partially understood. Nevertheless, these can be seldom measured or derived. Kinematic models, conversely, express such an interaction of complex variables as simple synthetic parameters, such as the amount of upward propagation of the fault tip for unit of slip, usually referred to as the P/S ratio (Propagation on Slip). Here, we discuss results on the trishear kinematic inverse modeling of a contractional fault propagation fold at Monte Netto Hill (Capriano del Colle, N. Italy), observing a two-stage fault and fold growth evolution, marked by a significant shift in the P/S parameter. At this site, exceptional sequence of exposures due to ca. 10 years of quarry excavations allowed to obtain a series of cross-sections across the fault zone. We use this detailed, high-resolution, example as a natural \u201canalogue\u201d for more general, large-scale surface ruptures involving a thick alluvial cover, a very common setting for the siting of critical facilities. During the early stage of displacement, the fault cut through clast-supported fluvial gravels with a high propagation rate (P/S\u202f=\u202f7) and a discrete rupture width. Then, during the latest movements of the thrust, fault tip propagation slowed down to P/S\u202f 48\u202f2.9, as the fault started cutting through several stacked bodies of clays and silty clays, pedogenized aeolian silts and overbank deposits, causing a pronounced folding of the layers over a wider deformation zone. These results strongly suggest that lithological changes in the underlying shallow stratigraphy, common in an alluvial plain depositional setting, would significantly affect the potential for surface faulting across the same tectonic structure, with relevant implications in the fault displacement hazard assessment

    The Khartoum-Omdurman conurbation : a growing megacity at the confluence of the Blue and White Nile Rivers

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    Khartoum is one of the largest cities in Africa, located immediately south of the junction of the Blue and White Nile rivers in central Sudan. The growth of the Greater Khartoum-Omdurman conurbation arose \uac\u2013 without a proper urban plan \u2013 from the agricultural wealth created through the completion of three major dams in 1925, 1937 and 1966, and mostly in the last three decades. Urban expansion was enabled by and helped to enhance the major agricultural expansion of the Gezira clay plains located to the south between the lower Blue and White Nile rivers. The confluence of the Blue and White Nile has been a focus of human settlement for at least 8,000 years, initially by semi-sedentary groups with a fishing-hunting-gathering lifestyle and later by Neolithic groups as shown by hundreds of archaeological sites. Today, Khartoum is a desert city and the hottest capital city on Earth, still very vulnerable to floods triggered by intense convectional storms. Such extreme events may become more common in future, representing a major geomorphological hazard in a city developed without urban plans. Moreover, uncontrolled urban and agricultural development is threatening most of the prehistoric cultural heritage of the region
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