中文摘要：

现生植物稳定碳同位素对环境的响应已有大量研究,但是化石植物碳同位素与古环境关系的研究却很少。浙江天台中新统嵊县组中含有大量保存精美的枫香叶片化石（Liquidambar miosinica）,为探讨利用化石叶片稳定碳同位素重建古环境提供了可靠材料。首先,分析了采自6个不同地区的现生枫香叶片（Liquidambar formosana）的碳同位素,获得它们的Δ~（13）C值,讨论其与温度、水分条件、光照水平等环境因子的相关关系。其中年极端最高温、年降水量和年日照时数与Δ~（13）C具有显著相关性,R~2分别为0.6,0.75和0.80,并建立了线性回归方程,显示出Δ~（13）C随着温度的升高而降低、年降水量的增加而增大,年日照时数的增多而降低。然后,将L.miosinica的Δ~（13）C代入3个回归方程中,计算出浙江天台晚中新世的年极端最高温、年降水量和年日照时数分别为39.2℃,1 329 mm,1 938 hrs.其中年降水量与采用其它方法恢复出的值相似,表明结果的可靠性,说明L.miosinica化石叶片碳同位素可以作为重建古环境的有效指示物。将重建出的晚中新世古环境参数进一步与现在的环境进行对比,发现与浙江天台比较相似,表明晚中新世浙东已演化出温暖湿润的亚热带气候。

英文摘要：

Stable carbon isotopic response of recent plants to environmental variation has been extensive- ly researched. However, the study on relation between carbon isotope of fossil plants and palaeoenvironments was seldom performed. Abundant well preserved fossil Liquidambar miosinica leaves were collected from the Miocene Shengxian Formation in Tiantai,Zhejiang Province,which provides reliable materials for reconstructing palaeoenvironments using stable carbon isotope of fossil leaves. Firstly, carbon isotopes of recent Liquidambar formosana leaves collected from six different sites were analyzed to obtain their carbon isotopic discrimination values （Al3C）. The correlations between Al3C and environmental parameters including temperature, water condition, irradiation condition, are established. The notable correlativity is found between Al3C and annual extremely warmest temperature（EWT） ,the mean annual precipitation （ MAP）, annual sunshine duration （ ASD）, and whose correlation coefficient values （ i. e., R2 ） are 0.60,0.75 and 0.80 ,respectively. It shows that A13C value is more positive with increase of MAP, but more negative with enrichment of EWT and ASD. Secondly, A13C of fossil L. miosinica leaves is substituted into three regression equations established above. The EWT, MAP, and ASD in late Miocene Tiantai, Zhejiang, are counted as 39.2℃, 1 329 mm and 1 938 hrs, respectively. The MAP is similar to that reconstructed from other methods, showing the result here is reliable. It suggests that stable carbon isotope of fossil L. miosinica leaves can be an indicator to reconstruct palaeoenvironment. Moreover, comparing to modern environment, the Late Miocene environment in Tiautai is parallel to that in same place, suggesting the subtropical climate has come into being in the Late Miocene for eastern Zhejiang.