Introduction to dolomite: Jizhou Karst Cave developed in the dolomite formation of the Hongshuizhuang Formation of the Changcheng System in the Middle and Upper Proterozoic. It is located in the Jixian Section of the "Tianjin Jixian National Geopark" and dates back about 1.2 billion years. Dolomite caves with such tourist value are relatively rare in northern my country and even the whole country.