The prominent utilization of chert raw material constitutes a defining characteristic of Early-to-Middle Late Pleistocene Paleolithic sites in the Daoshui River Basin, Hunan Province, Central South China. At the Tiaotougang site, for example, chert predominates, comprising 69.96% of the assemblage, followed by quartz sandstone (21.83%) and quartzite (7.92%). These chert materials exhibit diverse coloration, predominantly brown, yellow, and cyan, with secondary occurrences of white and red varieties. Quantitative quality assessment based on grain fineness, internal fissure density, and surface luster characteristics revealed three distinct grades of the chert in this site: good (grade 1, 9.54%), medium (grade 2, 47.28%), and poor (grade 3, 43.18%).

As all raw materials at Tiaotougang originated as river cobbles, this study prioritized gravel source tracing to investigate chert provenance. Comprehensive lithological surveys of bedrock, modern river gravels, and ancient fluvial gravels near the site indicate that the upper Daoshui River Basin contains relatively abundant and accessible chert resources. However, available chert consists predominantly comprises grade 2 and grade 3 cobbles, indicating medium-to-poor quality. Notably, while chert constitutes only 20%-30% of gravels in local riverbeds comparing with other lithologies, it dominates the assemblage of the Tiaotougang site. This significant discrepancy demonstrates that the site’s ancient inhabitants exhibited marked selectivity and organizational sophistication in exploiting chert resources, reflecting their sophisticated understanding of its superior flaking properties. Furthermore, lithic analysis reveals that medium-to-large tools were manufactured primarily from quartz sandstone and quartzite, whereas small tools were predominantly produced using chert. This pattern indicates hominins’ comprehensive understanding of the lithology-specific characteristics of different cobble types. Based on the spatial distribution of surveyed chert sources, we infer that most chert materials were procured locally from river gravels within a 1-2 km radius of the site. Critically, however, a small quantity of the highest-quality chert appears to have been intentionally procured from ancient terrace gravel deposits located approximately 10 km from the site.

Preliminary knapping experiments confirm that high-quality chert resources within the Daoshui Basin present no impediment to implementing sophisticated core preparation technologies, including Levallois reduction strategies and bladelet production techniques. The application of complex flaking methods in this region faced no raw material constraints and the persistent dominance of simplistic core-and-flake reduction sequences throughout the southern Chinese Paleolithic record cannot be attributed to limitations in raw material quality or availability. Consequently, this study provides new regional evidence challenging the long-standing paradigm that attributes the gradual trajectory of Chinese Paleolithic cultural evolution to deficiencies in high-quality lithic resources.