洞穴滴石石笋与陆地古环境记录研究进展

洞穴碳酸盐沉积与其它自然材料相比 ,具有分布广 ,时间跨度大 ,生长机制对环境敏感 ,保存信息完整 ,适合于 U系测年等特点。可与海洋沉积物、冰芯、树轮相媲美。尤其是洞穴滴石石笋为大陆气候替代指标提供了一类独特的数据源。从稳定同位素地球化学、石笋微层、微量元素地球化学、洞穴碳酸盐结晶学和岩石学等方面论述了该领域的最新研究进展。如利用洞穴碳酸盐δ函数定量地分离出纯的温度信号 ;利用石笋碳同位素变化及草原与森林生态系统光合作用的差异特征 ,恢复草原 -森林间的演变过程 ,显示了其在全球变化研究中的重要地位和作用。

STUDY ON CONTINENTAL PALEOENVIRONMENTAL PROXY BASED ON SPELEOTHEMS(DROP STONES)

Compared with other natural materials,speleothems have many superiorities,such as wide-ranging distribution,long-time span,sensitive to outside environment,full-scale information,suitable for U-series dating,and play the same important role as the sea deposits,ice-core,tree rings do.In particular,Cave dropstones-stalagmites offered us a kind of distinctive data source as continental paleoclimate archives.In this paper,the authors reviewed the advance in this field in detail from the stable isotope,stalagmite microbanding,trace elements geochemistry,petrology and crystallography of speleothems.For example,a pure temperature signal has been separated out from the records by utilizing speleothem delta function,and the history of changing vegetation has been traced by using the δ13C in speleothem calcite and the variation in the photosynthetic pathway of prairie plants compared to forest species.The advance has unfolded its importance in global change study.