岩溶洞穴中钟乳石类沉积物色泽变化的成因浅析

在溶洞开发利用过程中发现,一些原为晶莹洁白的洞内钟乳石类沉积物逐渐变得色泽暗淡发红或产生其它颜色,失去了原有的亮丽色泽.笔者认为产生这种现象的主要原因是由于洞穴开放程度增高或当地气候等环境条件发生较大变化,增强了洞内空气与洞外大气的循环交替,洞内空气中氧含量增大,造成渗入洞中水氧化还原条件发生较大变化,致使铁、锰等金属化合物在钟乳石类沉积物中沉积所致.此外,泥质、有机质以及其它金属矿物等在钟乳石类沉积物表面的沉积或附着,也是促使颜色变化的另一原因.

A BRIEF STUDY ON THE REASONS OF COLOR AND LUSTER CHANGE OF SPELEOTHEMS IN KARST CAVES

Some white crystalloid speleothems in karst caves become pallid red in color or other colors and lost its original color and luster after being opened. The author believes the leading cause of the change lies in metal compound, such as ferric and manganese compound, deposition on the speleothems. That is, when the cave is opened excessively or the local environment such as climate changes violently, the air inside caves will exchange more strongly with the outside atmosphere, and oxygen in the air will increase, that will results in the change of redox condition in the infiltration water, then sediment of ferric and manganese compound produced. In addition, the attachment or deposition on speleothems of mud, carbonic organic sediment and other metal minerals is another reason for the change in color.