The redbed karst morphs in southern Guangxi mainly include gentle hills, underground caverns, karst springs and subterranean rivers as well as karst windows. In 50m depth range under the ground, the caves are mostly non-filled cave of 0. 5 to 3 m high and the number of caves decrease with depth. The types of karst springs include rising spring and descending spring with big variation in spring flow. There is no subterranean river being found in the aquifers formed only with the redbed yet. The development and the morph features of the redbed karst in south Guangxi are related to lithology and geo-structure as well hydro-geologic conditions. The redbed karst in the area mainly develops in the calcareous conglomerate that formed on the margin of the redbed basin. The group structure of redbeds can be divided into single-bed and inter-bed type. The karst develops stronger in the single-bed type but the karst develops along bedding plane in inter-bed type. Usually ,the redbed caves is more developed near the contact zone of soluble rock and non-soluble rock layers; the redbed karst is much stronger and the cave is bigger near the fracture zone of fault or valley.%桂南红层岩溶形态主要表现为岩溶缓丘、地下溶洞、岩溶泉以及地下河、天窗等.在地下50 m深度范围,溶洞高0.5～3 m,多为无充填溶洞,发育数量随深度增加而减少.岩溶泉类型有上升泉和下降泉,泉水流量变化较大.目前尚未发现仅由红层作为含水层的地下河.桂南红层岩溶的发育程度及形态特征与岩性、构造及水文地质条件有关.红层岩溶主要发育于红层盆地边缘的钙质砾岩中.红层的层组结构可分为单一型和互层型,单一型岩溶发育相对强烈,互层型以岩溶顾层发育为特征.通常,在可溶岩与非可溶岩接触带附近红层溶洞发育;在断裂破碎带以及河各地带红层岩溶发育强烈,溶洞规模较大.
展开▼
