对新疆东疆北部巴里坤湖2.5m深的沉积剖面进行了年代学、沉积物粒度、TOC、磁化率和CaCO3含量分析,对比研究确定了巴里坤湖的碳库年龄约为750a,据此建立了研究剖面的年代序列。研究表明,各气候代用指标序列揭示了巴里坤湖地区全新世期间存在多次干湿气候波动,并伴随着一系列突发气候事件,其中有6次事件可以与全新世北大西洋浮冰碎屑事件及GISP2冰芯氧同位素记录进行良好对比,且呈现出显著约1.6ka的变化周期,表明高纬度北大西洋地区的气候变化可能通过对西风环流的影响与中国西北干旱区的气候变化密切相关。谱分析揭示出研究区气候变化还具有显著的200a,133a,108a和77a周期,可能与太阳活动周期有关。6300—5200cal a BP和4300—3500cal a BP期间巴里坤湖地区气候较为干旱,结合广泛的区域对比认为,中全新世干旱事件具有普遍性。
Through synthetic researches of multi-index geological records of Niya section, which are of high resolution in southern margin of Tarim Basin, this paper has reconstructed the sequences of paleoclimate in this region during historical times (since about 4000a B.P.). During the last 4000 years, the area has experienced alternations of relative cold-moisture and relative warm-dry periods. Three evident cold-moisture periods and three warm-dry periods are identifing. The study shows that the human activities have an intimate relation with the evolution of paleoclimate in the southern Xinjiang. Paleoclimate has played very important role in influencing human being′s agricultural activities.
ZHONG Wei, XIONG Hei-gang, TASHPOLAT Tiyip, SHU Qiang （Department of Geography, Xinjiang University,Urumqi 830046, P.R. China）
塔里木盆地南缘和田绿洲约特干遗址剖面多指标综合地记录到了近6.7 ka BP以来的环境变化。考虑到此地区人类活动的历史,各指标的变化记录了自6.7—4.0 ka BP期间环境变化的自然过程,揭示出6.5—6.7ka BP期间的显著湿润期以及出现于4.0 ka BP之后的转干和3.0 ka BP前后的相对冷湿期。自2.0 ka BP开始,人类活动的影响渐趋于显著。
