河南云台山世界地质公园红石峡谷形成年代研究

The Formation Age of the Hongshi (Red Rock) Canyon in the Yuntaishan Global Geopark,Henan Province

地貌年代是地貌学研究的重要内容,红石峡谷作为云台山世界地质公园重要的地貌景观与地质遗迹资源,其形成年代的研究具有重要科学意义。本文对红石峡谷地貌特征进行了详细野外调查及研究,通过地貌对比及释光法测年对红石峡谷的形成年代、新构造运动对峡谷的控制作用进行了探讨。红石峡谷具有年轻河谷的地貌特征:平面展布明显受构造节理控制、横剖面呈现V型、纵剖面为上凸形;用热释光法(TL)测得红石峡谷谷肩河流相砂砾石层泥质胶结物年代为(374.86±31.86)ka B.P.;与谷肩宽谷同期发育的灰岩溶蚀裂隙中蚀余红土的年龄为(340.74±28.96)ka B.P.;控制红石峡形成的黑龙潭断裂其分支断裂中断层泥年代为(300.04±25.50)ka B.P.。据以上证据并与子房河阶地级序及年代的综合对比认为:红石峡谷主要受黑龙王庙断裂的控制,形成于中更新世中期(Qp2-2)451—(374.86±31.86)ka B.P.之后。本研究利用测年数据对红石峡谷形成年代进行了定量约束,对太行山南缘地貌与新构造运动的研究具有参考价值。

The landform formation age is one of the important parts of the geomorphology. The Hongshi Canyon is an important landscape and geological heritage resource in the Yuntaishan Geopark,and its formation age has important scientific significance for the planning and construction of the geopark. The authors investigated the formation age of the Hongshi Canyon and its responses to neotectonics through geological investigation in such aspects as the plane shape,the cross-section,and the longitudinal profile,and made a comparison with the formation of Zifang Rivier terraces and the activity age of the Heilongwangmiao fault. It is shown that the Hongshi Canyon has the geomorphic feature of young valley,as evidenced by the facts that its plane form was affected by tectonic joint,the cross section shows V-shaped feature,and the longitudinal profile is convex. Moreover,the thermo-luminescence（TL） data show the age of the argillaceous cements in the fluvial gravel layer on the replat is about（374.86±31.86） ka B.P.,that of residual red soil of the same period in grike is（340.74±28.96） ka B.P.,and that of the fault gouge in the Heilongwangmiao secondary fault is（300.04±25.50） ka B.P.. The results indicate that the generation of the Hongshi Canyon was controlled by the Heilongwangmiao fault,and it was formed during the mid- Pleistocene（Qp^2-2） after 451—（374.86±31.86） ka B.P.. The results obtained by the authors provide a quantitative restriction for the formation of the Hongshi Canyon,and are also of some reference value for the study of geomorphology and tectonics in southern Taihang Mountains.