腾冲火山活动构造动力学研究

DYNAMICS STUDY OF TECTONICS ON TENGCHONG VOLCANO ACTIVITY

利用腾冲火山区域 (10°～ 35°N ,90°～ 10 6°E) 1990～ 1998年 6 6 0个地震基本参数和震源机制资料 ,以及原先已作过 370多个强震震源参数资料[1 ] ,并结合本区域的地质资料 ,对本区的火山作用的构造动力学以及腾冲火山与印度、欧亚两大板块的关系作了探讨。研究表明 ,腾冲火山区西侧的印度板块对缅甸板块和包括腾冲在内的滇缅泰板块作用 ,大致在 0～ 10 0km作用机制表现为斜俯冲 ,10 0km以下表现为碰撞挤压作用。分析还表明 ,腾冲火山的形成与活动 ,与印度板块和亚欧板块两个大陆板块俯冲、碰撞 ,及在缅甸那加山、阿拉干山板块缝合线产生的斜俯冲和侧面挤压剪切作用密切相关 ,它应该属于两个大陆板块碰撞型板缘火山。

Combining geological data in the area,the tectonic dynamics in Tengchong,relations between Tengchong volcanoes and India and Eurasia plates have been studied by focal parameters of 370 strong earthquakes that have been made previously and data of 660 earthquakes happened in areas of 10°-35°N and 90°-106°E in 1990-1998.The study shows that the action of India plate to Yunnan-Myanmar plate and Tengchong included Yunnan-Myanmar_Thailand plate is in the range about 0=100km.Mechanism of action is quite different comparing with that below 100km.The analyses indicate that the formation and activity of Tengchong volcano are related to the downthrust and collision of India and Eurasia plates.So,the volcanoes belong to a collision one.