华北峡谷珍品——河北野三坡“百里峡构造-冲蚀嶂谷”的成因

A treasure of the North China gorges-the Yesanpo “One-Hundred-li structural erosion gorge”: Its origin

野三坡国家地质公园位于紫荆关大断裂北端,河北涞水县境内。百里峡构造-冲蚀嶂谷由3条分裂嶂谷组成,总长达52.5km,发育在紫荆关大断裂东侧的中元古界雾迷山组燧石条带白云岩中。中—新生代4期宏大而直立的构造节理,特别是喜马拉雅期南北向追踪张节理,是嶂谷形成的先决条件;更新世阶段地壳迅速的抬升、外力的物理风化作用,特别是晚更新世间歇性山区洪水的冲蚀,是形成嶂谷的直接原因。百里峡构造-冲蚀嶂谷是喀斯特地貌中一种特殊的类型。

The Yesanpo National Geopark is located at the north end of the Zijingguan fault, in Laishui County, Hebei Province. The 'One-Hundred-li structural erosion gorge' (li is a Chinese unit of length (=1/2 km)) at Yesanpo is composed of three separated erosion gorges with a total length of 52.5 km. They are developed in cherty-banded dolostone of the Mesoproterozoic Wumishan Formation on the east side of the Zijingguan fault. There occur four Meso-Ceno gigantic vertical structural joints, which, especially the Himalayan N-S-trending tensional joints, are the prerequisite of the formation of the erosion gorges. The rapid crustal uplift in the Pleistocene and physical weathering and erosion, especially the erosional process of the flood in the mountains, are the direct causes for the formation of the gorges. The One-Hundred-li structural erosion gorge is a special karst geomorphologic feature.