Structural model of the central Longmen Shan thrusts using seismic reflection profiles: Implications for the sediments and deformations since the Mesozoic
Structural model of the central Longmen Shan thrusts using seismic reflection profiles: Implications for the sediments and deformations since the Mesozoic
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使用地震反射剖面的龙门山中部逆冲断层构造模型：对中生代以来沉积物和变形的影响
DOI：
10.1016/j.tecto.2014.05.003
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发表时间：
2014-09
期刊：
影响因子：
2.9
通讯作者：
Liu Bo
中科院分区：
文献类型：
--
作者：
John Suppe;Jonny Wu;Ma Yongsheng;Liu Bo
构造背景和变形历史是了解地震频发和灾害评估的重要方面。本文对2008年5月汶川7.9级地震后收集到的两条新的地震剖面进行了解释。我们的解释综合了4口井、3条地震剖面和地表地质资料，揭示了龙门山逆冲断层中部的构造特征。钻井资料表明，龙门山冲断带上三叠统和下三叠统存在两个滑脱。浅层滑脱断裂将其滑动转移到盆地，在四川盆地内部进行了另一次变形。在浅部滑脱之间，发育了许多断裂，逆冲前缘的主要构造形成了构造楔形。钻井和地震解释均显示上三叠统在深度上有重复。龙门山逆冲中段的缩短率约为30%-37%。根据地质调查和地震解释，龙门山前缘前陆盆地发育于晚三叠世，下侏罗统与上三叠统角不整合。中生代以来的几次不同构造事件表明，龙门山具有复杂的演化历史。在我们的模型中，龙门山中部的北川大断裂(F2)和彭关断裂(F3)在地表附近倾角较大，但在深部倾角较缓。浅层逆冲作用和基底缩短作用共同促成了龙门山新生代的快速隆升。同震破裂断裂类似于发育在主干断裂系统上的分支断裂。汶川Mw7.9地震和庐山Mw6.7地震可能与基底构造的反应有关。
The structural setting and deformation history are very important aspects of understanding the frequent earthquakes and assessing the hazards. In this paper, we interpret two new seismic profiles that were collected after the Wenchuan Mw7.9 earthquakes occurred on May, 2008. Our interpretation has integrated four wells, three seismic profiles and the surface geology to reveal structural characteristics of the central Longmen Shan thrust. The drilled wells reveal that there are two detachments within the upper Triassic and the lower Triassic at the Longmen Shan thrusts. The shallow detachment fault transferred its slip to the basin and made another deformation inner the Sichuan basin. Between the shallow detachments, many faults developed and the major structures at the thrust front have formed as structural wedges. Both the drilled wells and seismic interpretation show the upper Triassic repeated in the depth. The shortening at the central Longmen Shan thrust is approximately 30%–37%. According to geological survey and the seismic interpretation, the foreland basin was developed during the late Triassic and the angular unconformity between the lower Jurassic and the upper Triassic at the Longmen Shan front. Several different tectonic events can be identified since the Mesozoic, which indicated that the Longmen Shan has a complex evolution history. In our model, the major Beichuan fault (F2) and the Pengguan fault (F3) at the central Longmen Shan dip steeply near the surface but are more gentle-dipping at depth. Both of the shallow thrusting and the basement shortening made contribution to the rapid uplift of the Longmen Shan during the Cenozoic. The co-seismic ruptured fault is like a branchy fault that developed on the major fault system. The Wenchuan Mw7.9 earthquake and the Lushan Mw6.7 earthquake may be related to the reaction of the basement structures.
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影响因子：
2.9
作者：
Maomao Wang;D. Jia;A. Lin;L. Shen;G. Rao;Yiquan Li
通讯作者：
Maomao Wang;D. Jia;A. Lin;L. Shen;G. Rao;Yiquan Li
地震反射剖面揭示的龙门山冲断带中部锋带结构几何沿走向变化
影响因子：
2.9
作者：
Suppe, John;Ma, Yongsheng;Liu, Bo;Chen, Yuegau
通讯作者：
Chen, Yuegau
影响因子：
2.9
作者：
X. Nie;C. Zou;L. Pan;Zhaohui Huang;Dongming Liu
通讯作者：
X. Nie;C. Zou;L. Pan;Zhaohui Huang;Dongming Liu
影响因子：
2.9
作者：
A. Yin
通讯作者：
A. Yin
影响因子：
4.2
作者：
D. Yan;Mei‐Fu Zhou;Shubo Li;Guo-Qin Wei
通讯作者：
D. Yan;Mei‐Fu Zhou;Shubo Li;Guo-Qin Wei