利用深地震反射剖面研究北祁连─河西走廊地壳细结构

RESEARCH ON THE FINE CRUSTAL STRUCTURE OF THE NORTHERH QILIAN-NEXI CORRIDOR BY DEEP SEISMIC REFLECTION

在北祁连－河西走廊测制了一条深反射地震剖面．查明测区莫霍界面深４０－５０ｋｍ，向南倾向祁连山区．北祁连山前逆掩断裂面南倾，上陡下缓消失于３．５－４ｓ处（可能是滑脱带）．阿尔金断裂向东延伸到宽滩山深部，倾向南，下切到下地壳．阿尔金断裂带与北祁连道冲断裂带吸收了印度板块向北推移产生的压应力．

A 94 kilometer long deep seismic reflection profile was completed from northern Qilianmountain to Hexi corridor in Gansu province of China. The Moho is about 40─50 km deepand tilts southwards to Qilian mountain. The North Qilian Front Thrust is also dippingsouthwards, steeply in shallow with decreasing dip to merge with a reflection energy zone at3. 5─4 s, probably coming from a detechment. The Altun fault zone is likely extending eastto Kuantanshan, also inclined southerly and reaches the lower crust. It is the Altun faultzone and the North Qilian Front Thrust which absorb the press stress in Qilian regioncaused by the indian plate's northward movement.