滇西北新生代以来地球动力学背景及其环境影响

新生代、特别是第四纪以来，滇西北地壳活动增强：山脉的构造隆升速率从全新世以前的０．３～１．７ｍｍ／ａ变为全新世以来的２～７．１ｍｍ／ａ；全新世盆地的构造沉降速率较更新世增长１～２个数量级；第四纪断裂（以红河断裂为例）错移速率不断加大；现代地壳应力值高，构造变形速度快，地震活动强度加剧，地热流异常明显。地壳活动性加剧将造成滇西北地势格局和山地地质灾害问题进一步恶化、湖泊加速收缩、区域稳定性降低等一系列环境问题，人类生存环境将更严酷。

GEODYNAMIC SETTING SINCE THE CENOZOIC AND ITS ENVIRONMENTAL EFFECTS IN NORTHWEST YUNNAN, CHINA

Based on the detailed analysis data, it is found that tectonic movement in northwest Yunnan has been growing in intensity since the Cenozoic, especially in the Quaternary. Tectonic uplifting rate of various mountains changed from 0.4～1.7 mm/a before the Holocene to 2.0～7.1 mm/a since the Holocene, and the recent uplifting rate reached 4～15 mm/a. Tectonic subsidence rate of basins has been increasing in the Holocene by up to 1～2 orders of magnitude, compared to that of the Pleistocene. Displacement rate along fractures in the Quaternary (for example Red River fracture zone) has been accelerating continuously. Present crustal stress values are high, structural deformation rate is fast, intensity of earthquake has an obvious increasing trend, and terrestrial heat flow anomaly is very obvious. The intensification of tectonic movement above will bring about a series of problems on environment in northwest Yunnan, such as the relief framework and geological disasters of mountain land will be worsen, lakes in the region will contract acceleratively, and regional crustal stability will decline. Subsequently, mankind is facing a harsher living environment.