Morphometric analysis of middle stone age tanged tools from South-Western Libya, Central Sahara. A regional perspective

Morphometric characters of Middle Stone Age stone artefacts from SW Fezzan (Libya, Central Sahara) are investigated. The raw data set is composed of illustrations of tanged pieces from surface scatters and from one stratified and dated site. Both metric and shape analyses are used. The first is carried out on the basis of maximum artefact width and tang width from the whole data set; the second adopts Elliptical Fourier descriptors obtained from 2D contours of tanged points. The geospatial analysis of morphometric variability in a regional perspective shows some meaningful variations between artefacts coming from “highland” and “lowland” physiographic contexts. While the latter encompass most of the regional variability, the former seem to show a narrower range of variation, which could depend on a number of reasons including diverse chronology of occupation, different technological traditions or ecological constraints. The general data patterning is here interpreted in the light of the hypothesis that the water resources kept by the mountainous areas also under environmental stress possibly allowed them to act as a refugium during the most arid phases of the late Pleistocene. An intense occupation of the lowlands during similar chronological time frames and environmental conditions is less likely because of an inferable lower carrying capacity. The regional artefacts’ morphometric variability could thus mirror the population dynamics reconstructed so far for the study area: the record from the mountain ranges testifies for a residual occupation of humans skilled in arid survival, while the lowlands possibly hosted more varied population dynamics especially during cyclically earlier wetter conditions.