Evidence of Middle Pleistocene hominin migration in the Qinling Mountains (central China) from the Miaokou Paleolithic site

The Qinling Mountain Range (QMR) spans a large region in China and is an important area of hominin activities. Many Paleolithic sites are found in Bahe, South Luohe, and Hanjiang river valleys in the northern, eastern, and southern part of the range, respectively. The Danjiang River valley acts as a channel connecting these valleys and stretches from the north to the south of the QMR. The previous dating of the Paleolithic sites in the Danjiang valley mainly relied on geomorphologic comparison, stratigraphic correlation, fossil characteristics, and Paleolithic artifacts, indicating a lack of absolute data. In this study, we conducted a detailed geochronological investigation of the entire valley, and selected an ideal site-the Miaokou profile. Based on the identification of the loess-paleosol sequences, optically stimulated luminescence, and magnetostratigraphy, the Paleolithic artifacts of the Miaokou site located within the S5 and S6 layers of the profile belong to similar to 0.6-0.7 Ma. This suggests that the Paleolithic site is an old site in the Danjiang River valley, and this period also witnessed a rapid increase in the number of hominin sites during the Middle Pleistocene. Combining our results with previous reports across the QMR, we propose that the Danjiang River valley might have been a corridor for hominin migration, and is worthy of further investigation.