嘉陵江流域第四纪环境变化的沉积记录

Quaternary Environmental Changes Recorded inSediments of Jialing River Basin

嘉陵江流域对亚洲季风和西风环流变化响应敏感,研究流域第四纪环境变化对深入理解区域性地表过程和人地关系具有科学意义。系统分析了嘉陵江流域第四纪风成黄土、溶洞石笋、泥石流和古人类遗迹等沉积物记录的环境变化,指出了该区第四纪沉积环境研究存在的问题及未来方向。嘉陵江流域在早更新世期间气候较为稳定,以冷干为主,中更新世以后气候波动加大;在嘉陵江流域史前文明的扩散过程中,全新世气候波动起到了重要的推动作用。未来应加强沉积地层的时间分辨率、定量重建古环境、山原黄土环境指标提取、泥石流频发成因及石笋氧同位素的量化机制等方面的研究。

As Jialing River Basin is sensitive to Asian monsoon and western wind circulation,its quaternary environmental changes investigation is of scientific significance for further understanding of regional surface processes and man-land relationship.Environmental changes recorded in sediments of quaternary aeolian loess,cave stalagmites,debris flow and ancient human remains in Jialing River Basin are analyzed systematically.Problems existed in current research and future research direction are also pointed out.It is found that the climate is relatively stable,cold and dry during early Pleistocene;increased climatic fluctuations has occurred in middle Pleistocene and beyond;climate changes has promoted the spread of prehistoric civilization during Holocene.It is proposed that researches on the temporal resolution of sedimentary strata,quantitative reconstruction of paleoenvironment,environmental indicator extraction for loess in the mountainous area,causes of frequent debris flow and quantitative mechanism of oxygen isotopes in stalagmites should be strengthened in the future.