Explaining the Presence of Narrow-faced Bladelet Cores in Izeh Chipped Stone Assemblages and its relation to Population/Idea Movements in Late Pleistocene

Abstract: Several models of population/culture movements have been proposed based on bladelet production in Late Pleistocene of Eurasia. Narrow-faced bladelet/microblade cores, also known as "wedge shaped" cores in Central Asia and Far East studies, have been considered as a component of an inter-continent migration of people and idea which originated in Sibero-Mongolian region Upper Paleolithic and expanded to the northeast Asia, reaching to North America and Japan. there exists an extended publication which traces the diffusion of "wedge-shaped" or more precisely "narrow-faced" cores from their birthplace, supposedly at Siberia around 35,000 BP, expanding continent-wide at about 25,000-20,000 BP; such an expansion from Sibero-Mongolian region has been recorded in two directions, first to the east (Japan, Korea, Alaska, Northern America) and then to the west, to Western Central Asia. In this research narrow-faced cores are introduced from Paleolithic caves and rockshelters from southwest of Iran. Izeh Plain has been surveyed intensively, as a result of which 147 Paleolithic sites have been recorded. Chipped stones have been sampled in a controlled manner from the surface of the outer slopes of these caves and rock shelters. The chipped stone assemblage indicates a comparative chronology based on typical tools and cores which are attributed to Upper Palaeolithic (conical bladelet cores and their subtypes, carinated burins and scrapers, many bladelets, end scrapers, rare lamelle dufours), Epipalaeolithic (many bladelets, conical bladelet cores, geometric microlithis, backed bladelets, thumbnail scrapers), and Early Neolithic (pressure “Bullet Cores” and sickle blade/lets) in the Zagros region. Bladelet cores in Izeh assemblages could be classified into 8 different categories, including conical, semi-conical, flat-faced, bidirectional, multidirectional, irregular, carinated and narrow-faced cores. The latter includes 55 cores from 14 site which have been prepared in 3 different manners: 1. On natural tabular local raw material, using cortical faces as flat sides of the core; 2. Cores in which the two faces have been prepared by flaking and the platform has been shaped before the bifacial preparation; 3. A combination of the two first ones, in which one face is cortical and the other has been prepared by flaking.  The identification and classification of Narrow-faced bladelet cores from Izeh, which is a region far from the westernmost territory of Narrow-faced core models (i.e. southeast of Caspan Sea), raises questions regarding their connection to the movement paths from Central Asia to the west. The first and the easiest explanation for their presence in Izeh lithic assemblages could be in respect of the aforementioned population/culture movement patterns and the expansion of Sibero-Mongolian lithic traditions. But regarding the correlation between core forms to raw material natural forms in Izeh narrow-faced cores and the simultaneous presence of other bladelet core types, including prismatic and subtypes of prismatic cores, including conical, semi-conical and flat-faced cores, as well as carinated scrapers and burins, human population/idea movement models are not convincing enough for explaining the presence of narrow-faced core technology in Izeh Plain. Instead, local innovation and adaptation to environmental opportunities and limitations seems to be the most probable explanation based on the available evidence. Further studies on narrow-faced bladelet cores from Zagros Paleolithic assemblages could improve such a conclusion.