TU Nian1,2, ZHANG Jingya2, ZHANG Chengjun2
(1. The Radio and Television Group of Chongqing，Chongqing401120, China;
2. Key Laboratory of Mineral Resources in Western China (Gansu Province), School of Geological Sciences and Mineral Resources, Lanzhou University, Lanzhou 730000, China)
Abstract: Numbers of archeological relics of the Neolithic period were found to distribute in the Gansu-Qinghai area, upstream of Yellow River. At Chankou Dingxi (central Gansu, 35°44′11.7" N, 104°31′34.7" E), which is about 100 km southeast to Lanzhou, we found, for the first time, an archeological relic loess section. Pottery relics embedded in the first river terrace of the Chankou loess section in the Guanchuan River valley belonged to the Qijia Culture ( 5200-3700 cal a BP). A total of 178 sediment samples were collected and 5 AMS 14C age samples were determined in radioactive labs of BETA company and the Lanzhou University. The preliminary studies on these pottery relics indicated that this paleo-culture showed the primary closure characteristics, however, its backward production method received a few influences from the advanced production technology of that time, expressing the inherit to cultures along the silk road. To reconstruct the paleoclimate changes of this area since the last deglacial, paleoenvironmental proxies, like grain size, TOC content, carbonate content, elements and organic components of n-alkanes, were analyzed. According to the age-depth model from 5 AMS 14C data, the climate of this area was dry and cold before 13300 cal a BP, dry with little terrestrial plants during 13300-11200 cal a BP, warm and wet with a semi-dry forest-grass environment during 11200-5200 cal a BP, much dry and cold during 5200-3700 cal a BP, and dry to semi-dry grass environment with rare forest during 3700-2200 cal a BP. The human activities influenced this area from 2200 cal a BP to present. The Qijia Culture rose and declined during the dry and cold period, sited on the flood plain, indicating that, probably, the people lived mainly on the food plain of the first terrace near the Guanchuan River.
Keywords: Gansu-Qinghai Area; Qijia Culture; Chankou; Paleoclimate
EARTH AND ENVIRONMENT Vol.48, No.1, Tot No.333, 2020, Page 76-86