路南石林空气中水—石灰岩作用研究

LIMESTONE DISSOLUTION IN THE AIR IN SHILIN NATIONAL PARK, YUNAN, CHINA

土下溶蚀和雨水淋溶作用一直以来都被认为是石林景观形成的两种主要过程。石林地区雨水、地表水、溶窝水和溶沟水的水化学成分分析表明 ,溶沟和溶窝中的土壤、藻类、苔藓和地衣对石灰岩的溶蚀过程有很大的促进作用。碳酸盐岩岩面水作用可以分为直接和间接两种类型。以土壤和低等生物为媒介的间接溶蚀强度要大于雨水的直接淋溶作用。不同类型的水岩作用机理的差异和不同的溶蚀强度在石林景观形成过程中起决定作用。在溶沟下部采集的水样的电导率、TDS、HCO-3 和Ca2 + +Mg2 + 含量都大于在上部采集的样品 ,水在沿石壁向下运移的过程中溶蚀作用加强是因为水岩作用时间变长的缘故。

Subsoil erosion and dissolution by rainwater are the two mechanisms to form the Shilin landscape. During 1999 and 2000, we studied the chemical composition of rainwater, water in limestone pits and in the gully. There are different kinds of material in the limestone pit and gully, including soil, algae, lichen and moss. The depth of the soil in the gully may reach 20 to 30cm with grass and bush growing on. The study shows that material in the gully and pits greatly influence chemical composition of the water. Calcium concentration and conductivity of the water from the gully with soil is greater than that without soil and plant. In the limestone pits, water dissolution capacity is different with different kinds of material in them. We also collect water on the top and at the bottom from 6 gullys. The analysis results show that water collected at the bottom of the gully own greater calcium concentration, conductivity, total dissolved solid than the water collected on the top of stone column. In the process of dissolution in the air, the P CO 2 is constant, the increase of conductivity and etc. in the water may be attributed to the increase of reaction time.