辽河裂谷的深部构造与裂谷活动的侧向迁移
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摘要
对横穿辽河裂谷的闾阳－海城－东沟剖面的深部地震探测、重力测量、大地电磁测深、大地热流测量资料做了进一步分析，发现辽河裂谷地带壳幔间具有多个薄层过渡的特征，与东西两侧的辽东台隆和燕山台褶带明显不同。壳幔过渡带的薄层结构、速度结构、温度结构以及壳内低速层和软流圈顶面构造特点表明辽河裂谷的构造演化过程自西向东侧向迁移，当前上地幔物质运动的前锋不在裂谷之下，而是向东移至金州地震带附近的析木一带，深部物质运动是辽河裂谷形成及其活动性侧向迁移的主要动力学因素。
We have made further analyses to the geophysical data of Luyang-Haicheng-Donggou profile which transects the Liaohe rifting basin. These data include deep seismic sounding, gravity, magnetotelluric and heat flow measurements. It is found that the crust mantle transitional zone is characterized by the multi thin layers beneath the Liaohe rift which is quite different from those under the uplifted platforms on the both sides. The structural features of the thin layers, velocity, temperature, crustal low velocity layer and uppermost asthenosphere show that the tectonic evolution process has migrated from west to east for the Liaohe rift. The current front of movement of the upper mantle material has left from the center of the rift and moved eastward to the Ximu near the Jinzhou seismic zone. It is suggested that the movement of deep material is the primary dynamic factor for the generation and lateral migration of the Liaohe rift.
We have made further analyses to the geophysical data of Luyang-Haicheng-Donggou profile which transects the Liaohe rifting basin. These data include deep seismic sounding, gravity, magnetotelluric and heat flow measurements. It is found that the crust mantle transitional zone is characterized by the multi thin layers beneath the Liaohe rift which is quite different from those under the uplifted platforms on the both sides. The structural features of the thin layers, velocity, temperature, crustal low velocity layer and uppermost asthenosphere show that the tectonic evolution process has migrated from west to east for the Liaohe rift. The current front of movement of the upper mantle material has left from the center of the rift and moved eastward to the Ximu near the Jinzhou seismic zone. It is suggested that the movement of deep material is the primary dynamic factor for the generation and lateral migration of the Liaohe rift.
引文
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