As an important part of the Earth's Critical Zone, karst caves offer both scenic and scientific value. Little attention was given to the tectonic factors closely related to cave formation, and quantitative studies on the cave age are largely absent. This study focuses on the formation and age of the Xinglong Karst Cave in Taojiatai area of Hebei Province, based on detailed investigations of morphology, strata attitude, and tectonic characteristics of the cave, combining with mineral X-ray diffraction and geochemical element analysis. Results show that two faults are developed in the Middle Proterozoic dolomitic limestone with flint nodules, forming a fault-driven differential dissolution-type cave that extends downward along the fault. The geochemical characteristics of red clay deposits in the cave are similar to that of weathering crust outside the cave, and red stalactites are enriched with iron from surface water leaching, indicating that the red clay in the cave originates from outside. Therefore, the cave formation period should postdate the red clay deposits. Through regional comparisons, the surface residual red clay is the product of the Tangxian planation period (3.1~3.7 Ma), suggesting the cave formation age is later than 3.7 Ma. This study provides the first recognition that the Xinglong Cave is controlled by faults and effectively constrains its formation period, offering valuable references for research on the formation and age of karst landscapes in other regions.
DownLoad: