本项目聚焦西藏、云南等地代表性的温泉及其沉积的钙华，围绕温泉形成和钙华沉积的主题，针对钙华的物理特征和化学成分变化对环境演变的响应的关键科学问题，以钙华形态变化和钙华微层微量元素变化为核心内容，综合运用野外水文地质调查、现场观测和采样、室内分析和测试、理论分析、水化学模拟和对比分析等研究手段和方法，在查明沉积钙华的温泉的水文循环和钙华沉积影响因素的基础上，以近几十年温泉沉积的新钙华为突破方向，深入剖析钙华微层的物理特征和化学成分变化的原因，获得高分辨率的近几十年来和几十万年来的热水钙华微层物理特征和化学成分的记录及其所反映的环境演变的信息，建立热水钙华的沉积规模和形态变化以及热水钙华微层物理特征和化学成分的变化与环境演变的响应关系，揭示钙华微层Sr和Ba、Mg和Mn等的含量变化特征及其环境指示意义，阐明陆地温泉水文循环中物质迁移的方式和规律，丰富古环境重建的理论和全球气候变化的研究方法。

This proposed project focuses on the typical hot springs and the travertines depositing from the hot springs in Tibet and Yunnan and other places. The theme of the project is on the formation of the hot springs and the deposition of the travertines. Special attention is paid to the key scientific problem of the response of the changes in physical characteristics and chemical comositions of the travertines to the environmental evolution. The changes in morphology of the travertines and the changes in concentrations of trace elements of the travertines are taken as the core contents of this work. Hydrogeological field investigation, measurements and sampling, analyses and detection of samples, theoretical analyses, hydrochemical modeling and comparison are proposed to be carried out comprehensively in this study. Clear recognitions of groundwater circulation of the hot springs depositing travertines and controlling factors of the travertine depostion are obtained and are taken as the basis of this research. The new travertines depositing from the hot springs in the latest decades are considered as the breakthrough direction of this project. The occurrence and changes in physical characteristics and chemical compositions of the laminated travertines are analyzed in detail. Records of physical features and chemical compositions of the laminated travertines of tens of years and tens of thousands of years and the information reflecting the environmental evolution are obtained. The relationship between the changes in the size and morphology of the travertines and in the physical features and chemical compositions of the laminated travertines and the environmental evolution are established. Changes in the contents of Sr and Ba, and Mg and Mn of the laminated travertines and their indication of the environmental evolution are obtained. The research results are helpful in describing the form and law of substance transport in water circulation of a hot spring in a continental environment. The results are also of important scientific significance in enriching the theory of the reconstruction of paleo-environment and the research methods of the global changes in climate.