湘西保靖白岩洞-金塘湾洞穴系统的发育特征

DEVELOPMENT CHARACTERISTICS OF BAIYANDONG-JINTANGWAN CAVE SYSTEM, BAOJING COUNTY OF HUNAN PROVINCE

白岩洞 -金塘湾洞穴系统 ,由主洞和 10条支洞组成 ,呈高、中、低洞穴层相互串通的阶梯状结构 ,洞道长 12 km(仅探测 6 390 .4 m)。洞穴系统受下寒武统清虚洞组碳酸盐岩地层分布的控制 ,洞穴发育对中薄层灰岩和中厚层泥晶灰岩具有优选性 ,其展布方向受 NNE、NE向的破裂构造、揉皱破裂带的控制 ,表现出较强的方向性。本洞穴系统形成于白垩 -第三纪 ,至今仍在向纵深发育。洞穴系统演化的空间结构 ,由早期高层洞、中期中层洞、晚期低层洞依序演变 ,并由南西向北东逐级演化 ,在其演化过程中 ,为垂向、斜向、阶梯式洞道所串通 ,构成层楼式的网络状洞穴系统。

WT5BZ]The cave system of Baiyandong Jintangwan is composed of one main passage and ten branch caves, which shows the ladder like cave system with the upper, middle and lower cave levels connected with each other. The length of cave totals up to 12km (only 6361.6m explored). The cave system is controlled by the distribution of the strata of Lower Cambrian series's carbonate rocks. The medium thin bedded limestone and medium thick bedded crystalline limestone is preferred in the cave development. The distribution of the cave, which is controlled by NNE, NE fractures and kneed folded fracture zone, shows its remarkable orientation. The cave system formed in Cretaceous Tertiary period,it is still developing in the direction of vertical deep dissection now. The cave system evolution is from the upper layer cave formed in early stage,the middle layer cave in middle stage to the lower layer cave in late stage, and from southwest to northeast as well as from west to east gradually. The vertical, inclined and ladder like galleries link up with each other during the evolution process, which forms a network of cave system.