初论藻类生物岩溶作用

PRELIMINARY STUDY ON ALGAL BIOKARST

藻类的新陈代谢活动深刻地影响岩溶形成与发育。藻类呼吸作用产生ＣＯ２，遇水生成碳酸，分泌酸性物质、粘液及遗体经微生物分解，产生ＣＯ２等，这些物质对碳酸盐岩均有溶蚀作用；藻类的钻孔作用，使碳酸盐岩表层形成多孔状、网络状、从而增大其化学溶蚀的有效表面积、降低其物理机械强度。藻类通过同化作用、捕捉粘结作用等方式沉淀碳酸盐．藻类对碳酸盐岩的作用可产生特征性产物及生物成因显微结构构造．桂林岩溶区，以藻类生物溶孔计算，藻类对碳酸盐岩的最大钻孔溶蚀速率占区域混合溶蚀率的２０％。

The metabolism of algae has great influence on the karst formation and development. The respitration of algae releases CO2, and may form carbonic acid in the presence of water, Secretes organic acid and other acidic matter. And the microbes may degrade the organic matter and dead bodies of algae and released CO2 et al. The matter might cause limestome to be eroded. In addition as a result of the boring action of algae, the upper layer of limestone may be porous and network layer. At the subsurface of limestone, the effective area of chemical. erosion has increased, whereas the physical mechanic strength has decreased. The carbonate was precipitated by assimilation. trapping and binding and calcification of algae. The acition of algae on carbonate might form characteristic products, such as light-oriented stalactite in cave, cave stromatolites and bioerosional hole at the surface of limestone. In Guilin area, the biggest rate of algal boring and eroding is 17.87 mm / k.a and takes 20 percent in the total mixed erosional rate.