中文摘要：

层状钙华作为高分辨率古气候环境重建记录已被国内外许多学者所关注。钙华的微层厚度、氧碳同位素组成和微量元素的含量都呈现出随季节变化的周期性特点。钙华年层的形成与方解石沉积速率或者微生物生长活性的季节变化有关；氧同位素组成的变化主要受温度和沉积水体的δ^18O控制，但蒸发作用（尤其是在干旱区）也有重要影响；钙华的稳定碳同位素组成主要反映了不同6’℃的碳源对水体溶解无机碳（DIC）的贡献。CO2的逸出和水生植物的光合作用会带走水中的^12C，从而使δ^13CDIC值增加。此外，钙华中的Mg，Ba和sr等微量元素的含量与它们在水中的浓度和水温以及降雨量有关。然而，在钙华的高精度测年以及加积作用和再沉淀对同位素组成的影响等方面还需做进一步的研究。总之，层状钙华因其高沉积速率而在第四纪高分辨率占气候重建中有独持的优势，有可能成为第四纪研究的又一热点。

英文摘要：

It is wildly accepted that tufa and travertine with laminae can be used for high-resolution reconstruction of Quaternary paleoclimate. Alternating laminae of dense micrite and porous calcites, combined with stable isotope （δ^18O and δ^13C ）and trace elements from recent tufa show seasonal changes which reflect the climatic information. These alternating laminae have been interpreted to represent seasonally controlled differences in the rate of calcification and/or biotic activity of microbes. Variability in δ^18O is driven mainly by changes in water temperature and the δ^18O value of the recharging water, while evaporation, especially in arid climates, also needs to be accounted. Variability in δ^13C reflects principally the relative contribution of isotopically different carbon origins to dissolved inorganic carbon（DIC）. CO2 degassing as well as aquatic photosynthesis can take up 12C-enriched CO2 in water and thus leave isotopically heavier DIC, which can also be given rise to by precipitation of calcite along the stream or river flow path. Meanwhile, the contents of trace element （e. g. Mg, Ba, Sr） in tufa are supposed to be related to temperature, their concentration in water and rainfall. However, whether aggrading neomorphism and reprecipitation change isotope record of tufa, and reliable chronologies need further research. In a word, as these deposits accumulate rapidly,laminated tufas and travertines offer an excellent opportunity to study seasonality in Quaternary palaeoclimate,and may become a promising record in future research.