59 research outputs found

    Technological homogeneity within the Arabian Nubian Complex: Comparing chert and quartzite assemblages from central and southern Arabia

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    Nubian Levallois technology is the defining characteristic of the Middle Paleolithic or Middle Stone Age technocomplex known as the Nubian Complex. Until recently, this technocomplex was found exclusively in northeastern Africa; however, archaeological surveys conducted across the Arabian Peninsula in the last decade have expanded the known distribution of this technological phenomenon. Since 2009, researchers from separate archaeological missions have mapped sites yielding Nubian cores and debitage, and by extension Nubian technology, in the southern, central and northernmost parts of the Arabia Peninsula. Nubian Complex artifacts in central and southern Arabia were made using different raw materials: in Al-Kharj (central Saudi Arabia) Middle Paleolithic industries were made exclusively on quartzite, while in Dhofar (southern Oman) chert was the only knappable material available for use. Given these differences, we sought to examine the influence of raw material variability on core morphology and size. Contrary to initial hypothesis, this study finds that the differences recorded are not a function of raw material properties. In both areas, Nubian cores were reduced using the same technological systems producing a set of preferential blanks. Rather, the recorded differences from raw material constrains were primarily due to knapping accidents, which occur in higher proportions at quartzite-based assemblages from Al-Kharj (specifically the siret fracture) compared with the chert assemblages from Dhofar. In sum, we argue that raw material had little effect on Nubian Levallois core technology and was not a constraint on Nubian Complex artisans

    The Red Sea, Coastal Landscapes, and Hominin Dispersals

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    This chapter provides a critical assessment of environment, landscape and resources in the Red Sea region over the past five million years in relation to archaeological evidence of hominin settlement, and of current hypotheses about the role of the region as a pathway or obstacle to population dispersals between Africa and Asia and the possible significance of coastal colonization. The discussion assesses the impact of factors such as topography and the distribution of resources on land and on the seacoast, taking account of geographical variation and changes in geology, sea levels and palaeoclimate. The merits of northern and southern routes of movement at either end of the Red Sea are compared. All the evidence indicates that there has been no land connection at the southern end since the beginning of the Pliocene period, but that short sea crossings would have been possible at lowest sea-level stands with little or no technical aids. More important than the possibilities of crossing the southern channel is the nature of the resources available in the adjacent coastal zones. There were many climatic episodes wetter than today, and during these periods water draining from the Arabian escarpment provided productive conditions for large mammals and human populations in coastal regions and eastwards into the desert. During drier episodes the coastal region would have provided important refugia both in upland areas and on the emerged shelves exposed by lowered sea level, especially in the southern sector and on both sides of the Red Sea. Marine resources may have offered an added advantage in coastal areas, but evidence for their exploitation is very limited, and their role has been over-exaggerated in hypotheses of coastal colonization

    Technological homogeneity within the Arabian Nubian Complex: Comparing chert and quartzite assemblages from central and southern Arabia

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    International audienceNubian Levallois technology is the defining characteristic of the Middle Paleolithic or Middle Stone Age technocomplex known as the Nubian Complex. Until recently, this technocomplex was found exclusively in northeastern Africa; however, archaeological surveys conducted across the Arabian Peninsula in the last decade have expanded the known distribution of this technological phenomenon. Since 2009, researchers from separate archaeological missions have mapped sites yielding Nubian cores and debitage, and by extension Nubian technology, in the southern, central and northernmost parts of the Arabia Peninsula. Nubian Complex artifacts in central and southern Arabia were made using different raw materials: in Al-Kharj (central Saudi Arabia) Middle Paleolithic industries were made exclusively on quartzite, while in Dhofar (southern Oman) chert was the only knappable material available for use. Given these differences, we sought to examine the influence of raw material variability on core morphology and size. Contrary to initial hypothesis, this study finds that the differences recorded are not a function of raw material properties. In both areas, Nubian cores were reduced using the same technological systems producing a set of preferential blanks. Rather, the recorded differences from raw material constrains were primarily due to knapping accidents, which occur in higher proportions at quartzite-based assemblages from Al-Kharj (specifically the siret fracture) compared with the chert assemblages from Dhofar. In sum, we argue that raw material had little effect on Nubian Levallois core technology and was not a constraint on Nubian Complex artisans

    Headache as the only neurological sign of cerebral venous thrombosis: a series of 17 cases

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    Background: Headache is the most frequent symptom in cerebral venous thrombosis (CVT), and usually the first. However, it has rarely been reported as the only symptom of CVT. Objectives: To study the characteristics of patients in whom headache was the only presentation of CVT in the absence of intracranial hypertension, subarachnoid haemorrhage (SAH), meningitis, or other intracranial lesion. Methods: From a prospective study of 123 consecutive patients with CVT only those with isolated headache and normal brain computed tomography (CT) scan and cerebrospinal fluid (CSF) examination were included in the present study. All patients underwent an extensive systematic aetiological work-up and were given intravenous heparin followed by oral anticoagulants. A detailed description of the headache was obtained. Results: Headache was only sign of CVT in 17 patients. The lateral sinus was the most frequently involved sinus (n = 15). Onset of headache was progressive in 11, acute in 3, and thunderclap in 3 patients. Once established, the headache was continuous in 15, diffuse in four and unilateral in 13, usually ipsilateral to the occluded lateral sinus. No specific risk factor or cause was found. All had a favourable evolution. Conclusion: The pathogenesis of isolated headache in CVT in the absence of intracranial hypertension, SAH, meningitis or intracerebral lesion is unknown but may involve changes in the walls of the occluded sinus. Hence MRI/MRV should be used to look for signs of CVT in all patients with recent headache (progressive or thunderclap) even when the CT scan and CSF examination are normal
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