中文摘要：

笔者利用云南西部已有的DSS地震测深、石油反射地震资料的再解释，并通过地球物理、地球化学以及矿产等资料的综合分析．对滇西兰坪-思茅盆地内的中轴构造带的构造特征进行了深入分析。研究结果表明兰坪-思茅盆地内的中轴构造带是一条近南北走向的集断裂带、伸展构造、深部隆起为一身的大型构造带。地震测深的速度结构及反射地震剖面表明．中轴构造带在思茅盆地南部存在有深部地幔的上隆现象，该构造带内的断裂系统倾向在盆地南北有差异。研究发现该构造带与矿床、侵入碱性岩体及区域地化异常分布有密切的关系。结合地质构造分析研究，表明该构造带是一多期活动的重要构造带，具有伸展走滑的性质：中轴构造带在形成、演化过程中被近东西向的多条直线型断裂所错断．从构造形态上看与大洋中脊有相似的展布特征。该构造带对盆地的构造演化以及矿产形成具有重要控制作用。

英文摘要：

An intensive study has been conducted of the tectonic characteristics of the middle axial tectonic belt in the Lanping-Simao basin, western Yunnan, through reinterpretation of available DSS （deep seismic sounding） data and petroleum seismic reflection data and an integrated analysis of geophysical, geochemical and mineral resources data. Study indicates that the middle axial tectonic belt in the Lanping-Simao basin is a nearly N-S- trending large-scale tectonic belt integrating the fault zone, extensional structure and deep-seated uplift. The velocity structure of seismic sounding and seismic reflection profile indicate that mantle upweUing occurred at depth in the southern Simao basin of the middle axial tectonic belt. There is difference in dip direction of the fault system in the tectonic belt south and north of the basin. This tectonic belt is closely related to the distributions of mineral deposits, alkaline intrusions and regional geochemical anomalies. On the basis of the above study, combined with the tectonic analysis, the authors think that this tectonic belt is characterized by multi-stage activity and shows the extensional strike-slip characters. During the formation and evolution, the middle axial tectonic belt was dislocated by several nearly E-W-trending linear faults and has the distribution characteristics similar to those of the mid-ocean ridge in terms of the tectono-morphology. The tectonic belt has an important controlling effect on the tectonic evolution of the basin and formation of mineral deposits.