滇西北裂陷带的构造地貌特征与第四纪构造活动性

利用LANDSAT ETM+和ASTGTM数据构建了滇西北裂陷带三维可视化图像，并对区内各活动断裂带的构造地貌特征进行了解译与分析，然后针对该区31个主要断陷盆地，提取了多种指示边界断裂活动性的构造地貌参数，最后归纳了该区主要活动断裂的特点，并将活动性区分为强、中、弱三级。结果表明，该区主要活动断裂带的活动性存在明显差异性和分区性。整体而言，丽江—大理断陷带与程海—宾川断裂带活动性最为显著，其次为剑川断裂带，通甸—巍山断裂带的活动性在4组中最弱。总体而言，滇西北裂陷带的断裂强活动区域主要分布在边界上，在纬度上以南、北端的断裂活动性为最强，中部弱；经度上为中间弱，东、西两边较强，并且该区断裂活动性的分区性及差异与历史和现今地震活动性整体上是一致的，反映了断裂活动性与地震活动之间紧密相关。

Tectonic geomorphology and Quaternary tectonic activity in the northwest Yunnan rift zone

In this paper, 3D visual image was constructed to interpret the distribution and geometric structure characteristics of active faults based on LANDSAT ETM+/ASTGTM data obtained in northwest Yunnan Province, and then some basin parameters which indicated the fault activities were extracted from 31 basins. Finally, the characteristics of active faults were summed up, and their activities were divided into three grades, i.e., strong, medium and weak. The results show that there exist significant difference and zoning in the faults’ activities within this zone. The activity of the Lijiang-Dali and Chenghai-Binchuan faults are strong, that of the Jianchuan-Qiaohou faults is of the medium grade, and that of the Tonggian-Weishan faults belongs to the weak grade. Strong active faults are distributed around the boundary of northwest Yunnan rift zone. In terms of the latitude, the activities of the faults in the south and the north are the strongest, whereas those in the central part are weak. In the light of the longitude, the faults’ activities on both east side and west side are strong, whereas those in the central part are weak. The differences of the fault activities are on the whole consistent with historical earthquake activities.