关键词: 似奥杜威工业;遗址成因;早更新世;麻地沟E5地点;泥河湾盆地

Abstract: The Madigou (MDG) site provides a new archaeological sequence for the Early Pleistocene in the Nihewan basin, North China. This paper reports on the archaeological sequence, which is attributed to an Oldowan-like (Mode 1) industry. Emphasis is placed on analysis of site formation processes and lithic technology at the MDG-E5 Paleolithic site within the MDG site complex. The Madigou site complex is located in the key area of Early Pleistocene human occupation at the Cenjiawan Platform in the eastern part of the Nihewan basin. The MDG-E5 site was discovered in 2007 and was excavated by staff from the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences in 2014. A total of 22 m2 was exposed and 143 stone artifacts, eight mammalian fossil fragments, and 235 cobbles were unearthed from the site. The stratigraphic profile, 8 m in thickness, is comprised of grey-yellow, grey, and grey green fine sands, silts, and clays. The archaeological materials were located in grey-grey yellow fine sands and silts. The site is characterized by the concentrated distribution of gravels (roughly 4-8cm diameter) in which small numbers of stone artifacts are contained relative to dozens of cobbles and pebbles that are varied but size-sorted by hydraulic action. The current study thus indicates that MDG-E5 has been preserved in a secondary context in a lakeshore environment. Multiple lines of evidence include the distribution patterns of archaeological and natural lithic materials, size sorting, artifact abrasion, and spatial patterning. The MDG-E5 archaeological deposits most probably were buried in lake margins deposits of fine sands and silts that were moderately transported and disturbed by relatively moderate energy hydraulic forces. This indicates that the MDG-E5 artifacts have been buried and re-worked by natural agencies and are not in primary context. Technologically, lithic raw materials were procured from an adjacent area ca 1km2 in size, in which silicious dolomite, chert, and volcanic lava dominate the rock types. The flaking technique is direct hard hammer percussion without core preparation, and modified pieces casually retouched by direct hammer percussion. The flaking strategies morphology of the stone artifacts were simple, producing a Mode 1 assemblage which most resembles the Oldowan industry of Africa. Preliminary paleo-magnetic dating indicates that early humans colonized the site most probably at 1.20 Ma. Excavation of the MDG-E5 site is particularly significant for study of site formation processes, which helps us to interpret the adaptive behaviors of hominins in the Nihewan basin during the Early Pleistocene.

Key words: Oldowan-like industry; Site formation; Early Pleistocene; Madigou-E5 site; Nihewan Basin