【摘要】 【研究目的】塔西北中—晚更新世古环境变化的研究相对薄弱，西南天山作为亚洲气候环境变化的敏感区域，其古环境的研究对于预测未来气候意义重大，孢粉组合特征所指示的古植被演替规律已然成为该地区古气候研究亟待解决的重要问题。【研究方法】本文通过对新疆色帕巴依—柯坪地区河流阶地典型剖面样品孢粉鉴定和光释光定年测试，探讨了该区中—晚更新世孢粉组合特征及其对古气候的指示意义。【研究结果】划分出中—晚更新世三个孢粉组合带：第Ⅰ孢粉组合带：Quercus（栎）-Graminae（禾本科）-Chenopodiaceae（藜科）孢粉组合带；第Ⅱ孢粉组合带：Ephedra（麻黄）-Betula（桦）-Labiatae（唇形科）孢粉组合带；第Ⅲ孢粉组合带：Pinus（松属）-Ephedra（麻黄）-Chenopodiaceae（藜科）孢粉组合带。【结论】孢粉组合指示西南天山中—晚更新世总体气候干旱，呈干冷—暖湿—干冷的气候震荡趋势，其中65～16 ka期间存在明显的降水丰富的潮湿气候阶段；河流下切作用形成的阶地地貌受构造和气候双因素控制。更多还原

【Abstract】 This paper is the result of environmental geological survey engineering.[Objective] The study of paleo-environmental changes of Mid-to Late-Pleistocene in northwest Tarim Basin is relatively weak. As a sensitive area to climate and environmental change in Asia, the paleoenvironment study of the Southwest Tianshan is of great significance for predicting future climate. The succession law of palaeo-vegetation indicated by the characteristics of palynological assemblage has become an important problem to be solved urgently in paleoclimate research in this area. [Methods] Based on palynological identification and photoluminescence dating of typical river terrace samples from Sepayi-Keping area, Xinjiang, the characteristics of palynological assemblages in the Mid-to Late-Pleistocene and their implications for paleoclimate were discussed in this paper. [Results] Three palynological assemblages of Mid-to Late-Pleistocene were divided. Palynological assemblage zone Ⅰ: Quercus-Graminae-Chenopodiaceae; Ⅱ: Ephedra-Betula-Labiatae; Ⅲ: Pinus-Ephedra-Chenopodiaceae. [Conclusions] They indicate the arid climate of the Southwest Tianshan and the fluctuation trend(dry and cold-warm and wet-dry and cold) during Mid-to Late-Pleistocene.During 65-16 ka before present, there was an obvious humid climate stage with abundant precipitation. The terraces formed by river downcutting were controlled by both tectonic and climatic factors.更多还原