It has long been debated whether the formation of the Cenozoic Weihe and Shanxi grabens in North China was induced by the Indo–Asia collision or Pacific Plate subduction. Deciding between these two models requires precise knowledge of the timing of the graben formation. In this study, we used high-resolution magnetostratigraphy to suggest that the age of a ~ 1644-m thick syn-rift section conjoining the two grabens spanned from ~54.3 to ~3 Ma. The section is marked by three unconformities dated at ~26, ~12, and ~ 7 Ma. The precise ages, combined with field observations, indicate the following: the Weihe Graben underwent four rifting stages that started at ~54.3 Ma, whereas the Shanxi Graben opened at ~7 Ma. The synchronous timing between the basin development and uplift history of the Qinling Range strongly suggests that the Cenozoic extension across the Weihe and Shanxi grabens was coupled with left-slip faulting bounded at the northern edge of the Qinling. As the Qinling left-slip fault indicates eastward extrusion during the northward penetration of India, our work supports the early hypothesis that the opening of the north-trending rifts in North China was associated with the Cenozoic Indo–Asia collision. As the basin history across the Weihe and Shanxi grabens can also be correlated with the Bohai Bay evolution along the eastern margin of East Asia, the Pacific Plate may have also played a role in forming the two grabens. We conclude that the Cenozoic extension across North China has been controlled by both the Indo–Asia collision and back-arc tectonics induced by westward subduction of the Pacific Plate.

长期以来一直在争论华北地区新生代渭河和山西grab陷的形成是由印度－亚洲碰撞或太平洋板块俯冲引起的。要在这两种模型之间做出决定，就需要对the斗形成时间有准确的了解。在这项研究中，我们使用高分辨率地层学方法表明了厚约1644米的同化层的年龄。裂谷区与两个grab斗相连，跨度从〜54.3到〜3 Ma。该部分的特征是三个不合格日期分别为〜26，〜12和〜7 Ma。确切的年龄加上实地观察表明：渭河格拉本经历了四个裂谷阶段，开始于〜54.3 Ma，而山西格拉本开始于〜7 Ma。盆地发育与秦岭隆升历史之间的同步时间强烈地表明，渭河和山西grab陷的新生代延伸与秦岭北缘的左滑断层相结合。由于秦岭左滑断层表明印度向北渗透期间向东挤压，因此我们的工作支持了早期的假说，即华北向北的裂谷的开启与新生代印度—亚洲碰撞有关。由于渭河和山西grab陷的盆地历史也可以与东亚东缘的渤海湾演化联系起来，因此太平洋板块也可能在这两个grab陷的形成中发挥了作用。我们得出的结论是，华北地区的新生代伸展受到印度-亚洲碰撞和太平洋板块向西俯冲引起的弧后构造的控制。