Tectono-thermal modeling of Cenozoic multiple rift episodes in the Bohai Bay Basin, eastern China and its geodynamic implications
Tectono-thermal modeling of Cenozoic multiple rift episodes in the Bohai Bay Basin, eastern China and its geodynamic implications
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DOI：
10.1007/s00531-017-1550-1
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发表时间：
2017
影响因子：
2.3
通讯作者：
Qiongying Liu;Lijuan He;Lichun Chen
中科院分区：
文献类型：
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作者：
Qiongying Liu;Lijuan He;Lichun Chen
渤海湾盆地是中国东部最大的新生代裂陷盆地，具有多期性。采用二维多幕有限伸展模型，沿沿着6条地震剖面估算了每个裂谷幕的伸展因子和应变率。该模型是基于重建前裂谷地壳和岩石圈厚度，并与现今的热流和莫霍面深度进行校准。裂谷前地壳和岩石圈的厚度分别为34-39和80-105公里。拉伸因子在1.28到1.97之间，在始新世中晚期达到峰值，平均应变速率达到1.1 × 10− 15 s − 1。分析表明，新生代伸展中心总体上由南向北、由西向东迁移。结果还表明，平均应变率的变化与太平洋板块和欧亚板块之间的相对运动速率成反比关系。结合前人的研究结果，我们推测太平洋板块俯冲速率的变化伴随着俯冲带的幕式东退，对BBB的幕式伸展和伸展中心的东移起着重要作用。
The Bohai Bay Basin (BBB) is the largest Cenozoic rifted basin in eastern China, which exhibited a multi-episodic behavior. A 2D multi-episodic finite extension model is employed to estimate the stretching factor and strain rate for each rift episode along six seismic profiles. The modeling is based on a reconstruction of pre-rift crustal and lithospheric thicknesses, and is calibrated with the present-day heat flow and Moho depth. The pre-rift thicknesses of the crust and lithosphere are determined to be 34–39 and 80–105 km. The stretching factors range from 1.28 to 1.97, with a peak in the middle-to-late Eocene during which the average strain rate reached 1.1 × 10− 15s− 1. Our analyses show that the centers of stretching migrated generally from south to north and from west to east during the Cenozoic. The results also indicate an inverse relationship between variations of the average strain rate and the relative motion rate between Pacific plate and Eurasian plate. Combining the results of the previous studies with ours, we infer that the changing subduction rate of the Pacific plate accompanied by episodic eastward retreat of the subduction zone plays important roles in the episodic extension of the BBB and eastward migration of the centers of stretching.