中国西南现生淡水石灰华叠层石纹层机理及其高分辨率环境气候记录

项目名称： 中国西南现生淡水石灰华叠层石纹层机理及其高分辨率环境气候记录

项目编号： No.40872197

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 化学工业

项目作者： 田友萍

作者单位： 中国地质大学（北京）

项目金额： 59万元

中文摘要： 本项目通过对中国贵州、云南、四川、广西、湖北和山西等地的钙华进行考察，发现钙华可划分为4种类型：藻钙华、藓钙华、古钙华和热成因钙华。仅以蓝藻为优势物种的藻钙华，具有精细的纹层，是淡水石灰华叠层石，其他均不是。认为到目前为止，贵州黄果树是研究现生淡水石灰华叠层石的最佳地点，本项目确立了该地的最佳水样和沉积观测点。根据石灰华纹层特点和研究区降水量及河流流量年、月变化资料，研究认为石灰华叠层石的纹层特征是有沉积间断的季节纹层，其纹层厚度能反映当地的年、季节降水量，可通过数纹层定年，而蓝藻藻席是石灰华叠层石形成的必要条件之一。通过分析和验证研究区石灰华叠层石氧碳稳定同位素记录，揭示出贵州黄果树近200年来的气候环境变化，认为自1798年以来贵州黄果树气候变化分为6个阶段，分别为湿热、稳定、湿热、稳定、湿冷和干热，指出20世纪50年代以后，工农业发展迅速，植被破坏和生态恶化等一系列变化影响了气候环境自然发展的方向，目前气候环境正在向不同于20世纪50年代以前150多年的方向发展，即气候变暖。

中文关键词： 钙华；叠层石；高分辨率；气候；变暖

英文摘要： Tufas in Guizhou, Yunnan, Sichuan, Guangxi, Hubei and Shanxi etc., China were investigated in this project. It is thought that tufas may be classified into four types: algal tufa, moss tufa, old tufa and thermogene tufa. Algal tufas whose dominant are only blue-green algae are fresh water tufa stromatolites with fine line layers, and others are not tufa stromatolites. So far, Huangguoshu in Guizhou is the best place to study living fresh water tufa stromatolites. The best observed points of water and deposition were established. According to tufa layer characteristics, precipitation and river discharge changes data for year and month at research area, it is thought that tufa stromatolite layers are interrupted season layers and its thickness can reflect precipitation for years and seasons, and the layers can be dating by count layers. One of the essential conditions of formation of tufa stromatolites is blue-green algal mat living. Throught analysed and identified to δO andδC of tufa stromatolites, it is revealed that the climate and environment changes at Huangguoshu, Guizhou about last 200 years divided into six stages: damp and hot, stability, damp and hot, stability，damp and cold, dry and hot. A series of variety of the industrial and agricultural develops quickly, vegetation breakage and ecosystem worsened, etc. after 50's in 20th century, influence the natural direction of the climate and environment changes. Currently, the direction is differing from development direction of more than 150 years 50's in 20th century ago, namely the climate become warm.

英文关键词： tufa; stromatolites; high resolution; climate; warmimg