汉江上游早—中更新世河流地貌演化促进南秦岭山间盆地古人类扩散  

Drainage connection and terrace formation promoted early hominin occupation in the upper Hanjiang River during the Early-Middle Pleistocene

作　　者：张丹枫 王先彦[1] 张瀚之[1] 刘全玉 王社江[3,4] 鹿化煜[1] ZHANG Danfeng;WANG Xianyan;ZHANG Hanzhi;LIU Quanyu;WANG Shejiang;LU Huayu(School of Geography and Ocean Sciences,Nanjing University,Nanjing 210023,China;Colleage of Tourism and Environment Resources,Ankang University,Ankang 725000,Shaanxi,China;Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences,Institute of Vertebrate Paleontology and Paleoanthropology,CAS,Beijing 100044,China;Center for Excellence in Life and Paleoenvironment,CAS,Beijing 100044,China)

机构地区：[1]南京大学地理与海洋科学学院,南京210023 [2]安康学院旅游与资源环境学院,安康725000 [3]中国科学院古脊椎动物与古人类研究所、中国科学院脊椎动物演化与人类起源重点实验室,北京100044 [4]中国科学院生物演化与环境卓越创新中心,北京100044

出　　处：《地理学报》2023年第5期1213-1232,共20页Acta Geographica Sinica

基　　金：国家自然科学基金项目(41971005,42021001);国家社会科学基金重大项目(19ZDA225)。

摘　　要：秦岭与大巴山之间的汉江连通了汉中、安康等山间盆地,其间分布着众多旧石器遗址,是探究地貌过程对古人类活动影响的理想区域。本文通过黄土地层学、磁性地层学、碎屑锆石U-Pb年龄谱物源示踪,限定了安康盆地汉江高阶地时代及汉江自东向西贯通安康和汉中盆地的年代,讨论了轨道尺度气候变化背景下汉江地貌和水系格局演化对古人类在南秦岭山间活动的可能影响。结果表明:①汉江在安康盆地发育了8级阶地,其中第六级阶地形成于约1.82 Ma;②汉江阶地大多形成于间冰期—冰期转换期,且随着1.2 Ma中更新世气候转型与秦岭隆升速率的增加,形成更多的阶地;③汉江自东向西袭夺、贯通安康盆地和汉中盆地的时代不晚于1.82 Ma。河流袭夺和山间盆地连通为古人类在至少约1.5 Ma沿宽阔河谷往来秦巴山地提供了便利的地貌条件,此后形成的多级阶地为古人类提供了广阔的活动空间。The Hanjiang River,located between the Qinling and Daba mountains,connects the Hanzhong,Ankang and other intermontane basins where there are numerous paleolithic sites.Here is an ideal area to explore the impacts of geomorphic processes on hominin activities.In this study,based on loess stratigraphy,magnetostratigraphy and detrital zircon U-Pb geochronology,the age of high terraces in the Ankang basin and the time of the drainage connection of the Ankang and Hanzhong basins by the Hanjiang River from west to east was determined.In addition,the possible influence of the evolution of landform and drainage network pattern of the Hanjiang River on the hominin occupation in the southern Qinling Mountains in the context of orbital scale climate change is discussed.The results show that(1)Eight terraces of the Hanjiang River were developed in the Ankang basin,with the sixth forming at~1.82 Ma;(2)Most of these terraces were formed during the climatic transitions from interglacial to glacial periods,and more terraces were formed under the conditions of the Mid-Pleistocene climate transition(MPT)and the increase of uplift rate of the Qinling Mountains since 1.2 Ma;(3)It was not later than 1.82 Ma when the Hanjiang River connected the Ankang and Hanzhong basins as a result of river capture from east to west.River capture and the resulted connections of intermountain basins provided convenient geomorphological conditions for hominins to migrate into the Qinling and Daba mountains along broad river valleys since~1.5 Ma,and thereafter fluvial terraces provided beneficial space for hominin activities.

关 键 词：黄土地层 磁性地层 锆石U-Pb年龄 河流阶地 水系格局 古人类活动 安康盆地 

分 类 号：P931.1[天文地球—自然地理学] P597.3