方家沟遗址主文化层出土了大量石制品，以石片石器工业为特征，年代约在距今5~3万年前。遗址周边是一个石料资源相对丰富的区域，可以通过原料分布、质量和可获性了解当时人类为何选择特定原料。遗址的原料既包括石英砂岩、石英岩和脉石英砾石，又包括脉石英岩块。石料调查显示，遗址附近丘岗顶部的中更新世砾石层可能是砾石原料的来源；西北距遗址约7~11 km处的嵩山东南麓元古宙地层中多见脉石英出露，最有可能是脉石英岩块的采集地。遗址周边区域并不缺乏燧石等质量更好的原料，但极少被当时人类所利用，这说明当地石片石器工业的长期延续不能用缺乏优质原料来解释。

The Fangjiagou site, located in the southeast foot of Songshan Mountain and the east of Dengfeng basin, is an open-air Paleolithic site, and yielded abundant lithic artifacts from the main archaeological layer of the site dated to 50-30 ka BP. Its stone industry is characterized by flake tools. Surrounding area of this site presents a number of rock types of varying availability and quality for knapping, which can help to understand why hominins select specific lithic raw materials during MIS3. Here we report the results of investigation of raw material sources at the Fangjiagou site. We identified the lithology of lithic artifacts unearthed from the Fangjiagou site by hand-specimens, and analysed their prototype according to cortex-bearing pieces. The raw materials can be divided to three groups: Vein quartz blocks are dominant in quantity; Pebble/cobble forms including quartz sandstone, quartzite and vein quartz, also account for a certain proportion; In addition, there is a very small amount of flint, which only appears in the form of chips without cortex. We carried out geological survey within a radius of approximately 15 km of the site to identify potential primary and secondary sources for theses raw materials and compare outcrops with archaeological specimens. First, Middle Pleistocene gravel layer is widely distributed on the top of the hills near the site. According to the analysis of the gravel samples from two exposed sections(less than 1 km straight-line distance from the Fangjiagou site), the hominins mainly chose the rock types with relatively good quality from the gravel layer, and probably procure gravels by collecting ones eroded and peeled from stratum. Second, vein quartz are mostly exposed in the Proterozoic stratum at the southeast foot of Songshan Mountain about 7-11 km northwest of the site. The hominins collected vein quartz blocks around primary source areas and brought them back to make tools. We also investigated other rock outcrops in the study area even if they do not or rarely appear in the Fangjiagou site. In fact, there are potentially available tool-stones with higher knapping quality than vein quartz, such as flint outcrops near the Xishi site, and quartzite as vein quartz country rock. These stones are within the exploitation capacity for MIS3 hominins, but until the blade and microblade technology appeared by 26 ka BP in Dengfeng basin, the main raw material had always been vein quartz. This result challenges the explanations that attributing the lack of formalized lithic technology to raw material constraint factors in China.