滇西地区新第三纪孢粉组合特征及环境变迁

FEATURES OF SPOROPOLLEN ASSEMBLAGES AND ENVIRONMENT CHANGES OF NEOGENE IN AREA OF WESTERN YUNNAN

根据滇西地区７条实测剖面近１７０个孢粉样品的分析结果，对该地区新第三纪的孢粉组合特征进行了分析，并以此为基础反演了该时期的古植被、古气候及地形地貌特征，分析了滇西地区新第三纪自然环境的变化历史。认为：滇西地区新第三纪的古植被主要经历了由含针阔叶林→针阔叶混交林→山地针叶林→亚高山阴暗针叶林的变化；古气候由热带、亚热带向亚热带夹暖温带方向变化；地形地貌经历了由开阔的山间盆地与低山丘陵相间→准平原→高原的演化过程。

Based on more than 170 sporopollen samples from 7 profiles in the Western Yunnan (Dianxi) area, the characteristics of paleoflora, paleoclimate and paleolandforms are deduced,then the changes of the Neogene natural environment in Dianxi are analysed. The following conclusion may be obtained: (1) the Neogene paleovegetation in Dianxi mainly changed from broadleaf forests, including conifer to conifer-broadleaf mixed forests, through mountainous coniferous forests to subhighmountainous dark coniferous forests; (2) paleoclimates variation was from tropic-subtropic to subtropic including warm-temperate climates; (3) the paleolandforms were from open basins within mountains and lowmountains mixed with hills passing into peneplain, and finally to plateau.