地幔柱构造对松辽盆地及渤海湾盆地形成的制约

Mantle Plume Tectonics Constraints on the Formation of Songliao and Bohaiwan Basins

中国东部松辽盆地和渤海湾盆地形成与演化的深部动力学机制尚未得到很好的解释 .通过对区域地震资料盆地沉积记录、火山岩岩石探针和大地构造演化历史的综合分析 ,认为地幔柱 (柱头直径约 5 0 0km)在晚侏罗世 -晚白垩世时形成于松辽地区 ,经历了软流圈地幔上涌、地壳抬升与伸展、火山活动 ,导致松辽盆地的形成 ;由于华北板块向北移动 ,始新世时地幔柱 (柱头直径 6 0 0～ 80 0km)移动到京津 -渤海湾地区 ,类似的地质过程形成了渤海湾盆地 .

The dynamic mechanisms of the formation of the Songliao and the Bohaiwan basins, eastern China, are controversial. Based on the analyses of earthquake data, sedimentary record, volcanic probe and tectonic evolution, it is argued that the activity of mantle plume firstly undertook at the region around the Songhuajiang and the Liaohe rivers during Late Jurassic and Early Cretaceous time. The plume head was of 500 km in diameter at this stage. The Songliao basin formed due to the asthenospheric upwelling, crustal uplift and subsequent extension, and volcanic activity. However, the mantle plume, with 600-800 km head in diameter, would be beneath the Bohaiwan area in the Paleocene due to northwestward movement of the North China plate. The similar geological processes to the last stage undertook, and resulted in the formation of the Bohaiwan basin. Meanwhile, the plume is interpreted as the major factor of frequent earthquake at the Beijing-Tianjin and Bohaiwan area.