灞河和南洛河地貌演化对更新世古人类行为的影响

More than 60,000 lithic artifacts were discovered along catchments of Bahe River and South Luohe River over the past six years, in addition to the previous findings of human fossils such as cranium, mandible, incisor and fragments of skulls in Lantian, Luonan and Lushi, manifesting the Bahe and South Luohe Rivers are important places for the hominines living in the early to middle Pleistocene.Moreover, the Bahe River and the South Luohe River are located in the orogen of East Qinling Mountains, where have various and vulnerable fluvial landform and eolian silt deposition landform, which had rapid changes in the Pleistocene, generated by the active deposition and erosion processes. These put this region in an important position on investigating the relationship between the human evolution and the landform process impact. In this project, we will mapping the fluvial terraces, undertake the depositional analysis of both the fluvial and eolian sediments, work on the stratigraphy correlation and employ the techniques of optically stimulated luminescence dating, paleomagnetic stratigraphy analysis and the in situ cosmogenic nuclides 26Al/10Be to date several key sites. On the basis of these works, we will build the spatial-temporal evolution of the landforms along the Bahe and South Luohe rivers, with a time resolution of 100-150 ka and space resolution of 10-20 km. At the same time, we will analyze the over 410 lithic sites by the geographic information system (GIS) techniques, to identify the distribution of these sites, and their evolution with time, which would provide in detail information of the hominines behavior in the early and middle Pleistocene. Based on these landform mapping and the hominines behavior data, we will examine whether the landform had significantly impacted/controlled the hominines behavior and activity in the Pleistocene, and examine the maximum distance of the hominines activity at the key time periods. This would be the first to investigate the landform impact on hominines behaviors over the past circa 1.4 Ma in central China, and it would provide new understanding on the human behavior and the paleoenvironment.

最近六年，在中国中部灞河和南洛河流域又发现了近六万件的旧石器石制品，加上以前发现的蓝田人、洛南人和卢氏人等化石资料，表明该地区是更新世古人类密集活动的区域。灞河和南洛河流域地貌类型复杂多样，流水和风积地貌过程活跃，是开展地貌演化对古人类行为影响研究的代表性区域。本项目拟通过对两河的河流阶地位相图填图、阶地沉积物沉积动力分析和地层辨识，结合光释光、磁性地层和26Al/10Be宇成核素埋藏年代测定，在气候地层分析的基础上建立该区域约1.40 Ma以来地貌演化的时空过程（时间分辨率达0.1-0.15 Ma；空间分辨率为10-20 km）；通过对超过400处旧石器遗址点的地理信息(GIS)分析，认识古人类活动空间分布特点，揭示河岸、山地、岗地和平原等地貌类型对古人类行为的影响，探求早更新世以来地貌演化对人类活动的控制作用，增加对人类演化与地貌环境关系的新认识。

随着北半球大冰期的开始和中更新世冰期-间冰期的旋回，中国北方堆积了厚层的黄土沉积，同时中部和东部河流阶地发育。中国境内古人类在季风区长期生存，一直持续到晚更新世。在本项研究中，我们调查了东秦岭山区的灞河和南洛河流域大量早期人类的遗迹和遗物，并与本项目前期测年和古人类生存环境研究结果相结合分析。结果表明，早期人类主要沿河流，特别是中型河流流经的盆地，以及湖岸地区居住；在这些人类活动的密集的区域，人类居住地的分布还与植被格局有一定关系。即使在相对较近的地质历史时期，季风气候影响下的沙漠-黄土过渡带的沙地面积的扩展和收缩和区域植被格局的变化都与早期人群的繁盛和衰败有着密切的关系。在季风气候下，河流地貌形成，植被和土壤发育，为人类早期适应提供了重要背景。