喀斯特洞穴晶体生长速率的古气候重建意义

Karstic Cave Crystal Growth Rate and Its Significance in Climate Reconstruction

为了从石笋中提取更多的古气候信息,以用于气候预测,需要研究现代洞穴沉积过程与周围环境变化的关系。本文通过对贵州5个洞穴现代沉积玻片上菱形方解石的长度与滴水变率观测研究发现,在洞穴滴水不间断的情况下,滴水变率较小的滴水点,菱形方解石晶体长轴生长速率较快,反之,生长速率较慢。反映在石笋中,石笋晶体粒径较大说明处于降水稳定时期,石笋晶体粒径较小指示沉积时期降水变率较大,气候不稳定。

Developing paleo-climate information from stalagmites enables us to understand the characters and laws and forecast the climate. We need to study the sedimentary process of caves and the rules of surrounding env!ronment. According to the sta- tistics of the length of modern sedimentary diamond calcites and the drop variable rate of five caves in Guizhou Province, in the case of ceaseless cave water, the lesser the water drop is, the faster the growth of diamond calcites will be. Conversely, dia-mond calcites grow more slowly. For stalagmites, the larger size of stalagmite crystals indicates that the rainfall is steady, and the smaller size indicates that the precipitation variability is larger and the climate is in steady.