The Analysis Of Charred Plant Seeds At Jinchankou Site And Lijiaping Site During Qijia Culture Period In The Hehuang Region,China

Qijia Culture was one of the main cultures in the Gansu-Qinghai Region during the prehistoric period. And the sites of Qijia Culture were widely distributed in the Western Loess Plateau and northeastern Tibetan Plateau. Among these regions, the Hehuang region was one of the most concentrated areas of Qijia cultural sites distribution. During the Qijia culture period (2300-1500BC), prehistoric cultures exchange between east and west was more intensive and frequent than previous. As important elements of intercontinental cultural exchange between communities living in different parts of Eurasia, the study of the metallurgical technology, animals and plants during that period has been widely concerned at home and abroad. Based on the archaeological investigations of Jinchankou site and Lijiaping site located at the Hehuang region, we systematically collected77soil samples at Jinchankou site and13soil samples at Lijiaping site for flotation, and then the analysis of charred plant seeds. According to the collected1213L soil at Jinchankou site and127L soil at Lijiaping site for flotation,11243and3447of charred plant seeds at the two sites were identified respectively. Based on the statistical analysis of charred plant seeds unearthed at Jinchankou site and Lijiaping site, as well as1314C radiocarbon datings, combined with archaeological materials, we discuss the status of human plant resources use. We also discuss the spread process of early barley and wheat originated from West Asia in the Hehuang region during the Qijia period. Main conclusion as following:(1) The Jinchankou site was occupied by Qijia society during2200-1750BC. We identified10163charred plant seeds, including7055charred foxtail millet seeds,2821charred broomcorn millet seeds,271charred barley seeds,15charred wheat seeds and1charred hemp seed, the sum of which account for90.4%of total identified charred seeds. (2) The Lijiaping site was occupied by Qijia society during1750-1450BC. We identified2844charred plant seeds, including1989charred foxtail millet seeds,561charred broomcorn millet seeds,286charred barley seeds and8charred wheat seeds, the sum of which consist of82.5%of total identified charred seeds.(3) Wheat remains firstly appeared at Jinchankou site between2030-1890BC, which are considered as the oldest wheat remains in the Qinghai Province at present. However, the earliest time of charred wheat seeds appearance is later than that of charred foxtail millet seeds. The earliest charred barley remains were found at Lijiaping site between1760-1530BC.(4) The absolute numbers and ubiquities of charred millet remains are significantly higher than those of charred barley seeds and charred wheat seeds, indicating that the most important human subsistence strategy at two sites during2200-1500BC was millet-based agriculture, while with wheat and barley as auxiliary crops.(5) The role of barley was more important than that of wheat at two sites during2200-1500BC period, probably due to the adaptability of barley to the climate of high plateau margin prevail over that of wheat.(6) Compared to domesticated plants evidence and dating material at other sites in the Gan-Qing region, our result shows that wheat and barley firstly arrived in the Hehuang region of the central Gansu Province and northeastern Qinghai Province based on millet-dominated agriculture via Hexi Corridor-Biandoukou-Datong River valley during2200-1500BC period. However, it might have taken a long time for wheat and barley to introduce initially into regions based on millet-agricuture to the dominant crops.