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植物孢子和花粉是理想的恢复环境变化的有机指标,对于第四纪地层划分和区域古气候的对比具有重要意义。本文在川西冕宁泸沽镇附近选取安宁河Ⅰ～Ⅲ级阶地剖面进行年代学测量和孢粉采样分析。结果表明:安宁河Ⅰ级阶形成时期为全新世,气候温和较湿或轻湿;Ⅱ级阶地沉积时期在晚更新世晚期或全新世早期,温度及湿度均比Ⅰ级阶地时低,在该时期无论植被和气候曾出现过两次以上比较明显的变化及波动;Ⅲ级阶地沉积时期为晚更新世中期,气候温和较湿或轻湿,堆积时期之温度及湿度均比Ⅱ级阶地时高,但又均比Ⅰ级阶地时低。同时探讨了安宁河阶地形成时期构造、气候的变化规律。根据河流的下切速率可以间接的推断晚更新世构造隆升速率大于晚更新世末期-全新世。
Plant spores and pollen are ideal organic indicators for the restoration of environmental changes, and are of great significance for the comparison of Quaternary stratigraphy and regional paleoclimate. In this paper, the Quaternary Mudning Lugu town near the Anning River Ⅰ ~ Ⅲ terrace terraces for geochronology and sporopollen sampling analysis. The results show that the formation of the first-order stage of the Anning River is Holocene with a mild or wet climate; in the Late Stage of Late Pleistocene or Early Holocene, the temperature and humidity are lower than those in the first terrace, During the period of No. 2, there were more obvious changes and fluctuations in vegetation and climate. The Ⅲ terrace was deposited in the middle of late Pleistocene with a mild or wet climate, and the temperature and humidity in the accumulation period were higher than those in the Ⅱ terrace , But both lower than the first terrace. At the same time, the law of tectonic and climate changes during the formation of Anning River terraces was discussed. According to the river undercut rate, it can be inferred that the late Pleistocene tectonic uplift rate is larger than that from Late Pleistocene to Holocene.