Paleomagnetic data from Kope-Dagh, Northeast Iran

This dataset includes paleomagnetic data from 70 sampling sites, collected in northeastern Iran during two campaigns carried out in August 2016 and September 2017 (Table 1). The data are supplement to Mattei et al. (2019). Data allow to reconstruct the rotation history of the outer margin of the Eurasia-Arabia collision area represented by the Ala-Dagh, Binalud and Kopeh-Dagh mountain belts. The sampled formations are red beds units from the Lower Cretaceous Shurijeh Fm. and from the Middle-Upper Miocene Upper Red Fm (URF). Paleomagnetic results from all the sampled areas show a homogeneous amount of clockwise (CW) rotations measured in the above-mentioned Formations. These paleomagnetic results suggest that the oroclinal bending process that caused the curvature of Alborz mountain belt in north Iran after the Middle-Late Miocene, also extended to the Ala-Dagh, Binalud and Kopeh-Dagh mountain belts, at the north-eastern border of the Arabia-Eurasia deforming zone. This pattern of vertical axis rotations is inconsistent with the present-day kinematics of the northern Iranian blocks as described by seismicity and GPS data, suggesting that the tectonic processes responsible for the bending of northern Iran mountain chains are no longer active and that the westward motion of the South Caspian basin, and therefore the initiation of opposite strike-slip motion along the Ashk-Abad and Shahrud faults, occurred very recently (∼2My ago).

本数据集包含来自伊朗东北部70个采样点的古地磁数据（paleomagnetic data），这些数据通过2016年8月和2017年9月开展的两次野外考察获取（表1）。该数据补充了Mattei等人（2019）的研究成果，可用于重建以Ala-Dagh山脉、Binalud山脉和Kopeh-Dagh山脉为代表的欧亚-阿拉伯碰撞区外边缘的旋转历史。采样地层为下白垩统Shurijeh组及中-上中新统Upper Red组（URF）的红层单元（red beds units）。所有采样区域的古地磁结果显示，上述地层中存在均匀的顺时针（CW）旋转量。这些古地磁结果表明，中-晚中新世后导致伊朗北部阿尔博兹山脉弯曲的造山带弯曲过程（oroclinal bending process），同样延伸至阿拉伯-欧亚变形带东北边界的Ala-Dagh山脉、Binalud山脉和Kopeh-Dagh山脉。这种垂直轴旋转模式与地震活动性（seismicity）及GPS数据所描述的伊朗北部地块现今运动学（kinematics）特征不一致，表明导致伊朗北部山脉弯曲的构造过程（tectonic processes）已不再活跃；同时，南里海盆地的向西运动——以及由此引发的沿阿什哈巴德断层和沙赫鲁德断层的反向走滑运动的启动——发生于近期（约2百万年前）。