恭城-栗木断裂带中的断溶角砾岩——一种新型断层岩

通过对恭城－栗木裂带中断层岩的研究，确立了一种新型断层角砾岩－断溶角砾岩的存在。断溶角砾岩兼具断层角砾岩和岩溶角砾岩的特点，是断裂和岩溶塌陷共同作用的产物。这种角砾岩的角砾分为断层角砾和溶洞崩塌角砾两种，角砾及胶结物中均发育有方解石e双晶等应力作用的产物，它形成于地下5－8km深的脆性变形环境中，并记录了断裂带的多期活动及运动方向和应变型式。对断溶角砾岩的研究有利于恢复恭城－栗木断裂带的形成及其演化历史。断溶角砾岩形成模式的提出揭示了研究区与断裂伴生的地下溶洞的分布形成、发展及灭亡的规律，这对于减少或防止因溶洞塌陷而带来的地质灾害具有重要意义。

STUDY OF THE FAULT-KARST BRECCIA OF GONGCHENG-LIMU FAULT ZONE:A NEW KIND OF FAULT ROCKS

The fault rock research enables the authors to expound the existence of a new kind of fault breccia:fault karst breccia in Gongcheng Limu fault zone.The characteristics of fault karst breccia are the combination of fault breccia and karst breccia.It is a product of fault actions and karst collapses.The breccia includes fault breccia and karst breccia.The products of stress field grew both in breccia and in cement such as calcite e twins.The fault karst breccia has been formed in a brittle deformational environment,5-8 km deep under ground,which can show not only the repeated movement and movement direction of the fault zone but also the strain style.The research of fault karst breccia is beneficial to uncovering the formation history and evolution of Gongcheng Limu fault zone.Its patterns also can tell the regularity of the distribution and development of the underground karst caves,attached to the fault zone in this area.The fault karst breccia research is of great significance to decrease or prevent geological hazards resulted from the karst collapse.