## 4 Discussion
### Attribution of Ancient Cultural Groups  
A comparative analysis was conducted between the lower reaches of the Yuanjiang River and both the middle reaches of the Yuanjiang and the Lishui River Basins to explore the influence of different geographical environments on ancient cultures. The study revealed several similarities between the Wushui ancient cultural group and the lower Yuanjiang River ancient culture region, particularly in their use of riverbed gravel for making stone tools [19; 25]. Both cultures primarily produced single-sided blades approximately 15 cm long and emphasized large chopping and smashing tools. However, significant differences also existed. The Wushui group predominately utilized banded metamorphic sandstone, while the lower Yuanjiang River region is characterized by a variety of siliceous rocks, with fewer occurrences of metamorphic sandstone. The sharp edge smashing technique seen in the Wushui ancient cultural group, akin to methods from Guizhou's Maomao Cave, was absent in the lower Yuanjiang River, where stone fragments were generally thicker and featured flat gravel tabletops with concentrated impact points. In terms of chip production, the lower Yuanjiang River employed both single-sided and double-sided strikes, processing both the fracture and back surface of stones. In contrast, the Wushui cultural group exclusively used single-sided slicing without any secondary processing. The Wushui cultural group displayed a more uniform range of vessel types, lacking the slender triangular pointed vessels presented in the Wushui cultural group. Both cultures utilized chopping tools, but the Wushui cultural group typically struck one side of a long piece of flat gravel, while tools from the lower Yuanjiang River might have involved single-sided, double-sided, or bi-directional strikes. The paleolithic rocks in the lower reaches of the Yuanjiang River also shared significant similarities to those of the Lishui cultural group [19; 25; 40]. Both regions employed riverbed gravel for stone tools, including quartz, flint, quartzite, siliceous rock, and sandstone, though the proportions of these materials varied. Hammering techniques for chip pro duction and tool repair were common in both areas, with single-sided chip cutting being prevalent, alongside some instances of double-sided techniques. Tool processing generally involved striking both the fracture surface and the back, yielding thick stone fragments with flat gravel surfaces and concentrated impact points, notably different from the sharp-edged fragments of the Wushui cultural group. Both regions predominantly featured large stone tools, with small tools being rare. However, a trend towards miniaturization emerged in the Lishui River Basin during the late Paleolithic era. Similar combinations of stone tools existed in both areas, including pointed tools, scrapers, stone balls, and chopping tools, with triangular pointed objects being common. The pointed tools in the lower Yuanjiang River were slender and elongated, differing from the short dorsal pointed vessels found in the Wushui cultural group. The production processes and shapes of triangular pointed vessels and stone balls were consistent between the two regions [19; 25; 40]. Despite these similarities, the stone tools in the lower Yuanjiang River appear to be more monotonous. Although there were some similarities in production techniques and shapes of pointed vessels, the Lishui cultural group exhibited greater diversity. The lower Yuanjiang River contained fewer large chopping tools, likely due to its shorter archaeological development compared to the Lishui River Basin [25; 31]. While both regions predominantly featured large stone tools, those in the lower Yuanjiang River tended to be smaller and less robust than those in the Lishui cultural group, resembling tools from the Wushui cultural group.