On the Transformation of Stalagmite Texture and Structure

The study of many profile sections of stalagmites indicates that there are three types of stalagmite mineralogical composition:calcite type,aragonite type,and calcitea ragonite type or aragonite-calcite type.The texture,structure,depositlamina characteristics of them are similar to each other and exist in the whole growth process,but the microg ranular texture,the radiating,lamina(or micro-lamina) structures of aragonite stalagmite are more remarkable.The transformation of the texture and structure represents two a spects chiefly:the crystaltrans formation of aragonite to calcite;the secondary enlargement of the crystal which lead to the sustained crystallization.The a ragonite transformin to calcite reserving its acicular and prismatic crystals,presenting the pseudomorphy of a ragonite.The calcite recry stallization often reserves the granular,rhom bohedron,scalenohedron,multipletwin,prismatic,and tabular crystals.The conversion of the stalagmite texture and structure and the strength of the calcitization depend not only on the climate environment,dripping water(or condensation water)from seep age water in the cave but also on the moisture content of the stalagmite.The crystallization, calcitization,and conversion of the carbonates is completely under the normal(or low)temperature and (or low)pressu reconditions in which there is no foreign substances,as well as no effect to the isotopic fractionation and the information of paleo-climatic environment from the stalagmite records.The whole process plays a part of perfect self-regulation.So,the study on the conversion of stalagmite texture and structure is of great theory and practice significance in palaeoclimatic and paleo environmental recon struction,ecological rehabilitation,mineralogy and crystallog raphy,isotopicdating,and correction and so on.