颗石形态学及古海洋学应用

MORPHOLOGY OF THE COCCOLITH AND ITS APPLICATION IN THE PALEOCEANOGRAPHY

颗石藻是一种单细胞海洋钙化浮游藻类,可以在细胞周围产生方解石质的颗石。颗石藻细胞死亡后,散落的颗石可沉降至深海,保存在海洋沉积物中。自白垩纪以来,颗石就是海洋中碳酸钙的重要贡献者,其丰度和形态(大小、厚度、重量)决定了大洋“碳酸盐泵”的强度。室内培养实验和地质记录都表明颗石藻钙化作用及颗石形态对环境因素如温度、盐度、光照以及pH等非常敏感,因此颗石形态学分析在海洋碳循环与古气候研究中具有重要意义。本文对颗石形态学在古海洋研究中的应用进行了综述,重点介绍了颗石形态学参数测量方法,尤其是颗石重量的测量方法,并介绍了颗石钙化作用指标,如颗石大小、重量在古海洋学研究中的应用。

Since the Cretaceous,the coccolithophores that produce coccoliths inside its cells,has been a significant source of calcium carbonate in the oceans.The size and abundance of coccoliths determine the strength of the "carbonate pump" in the open ocean.The morphology of coccoliths is extremely susceptible to the environmental conditions such as temperature,salinity,light,and p H,as both culture experiments and geological records have demonstrated.Therefore,measuring the coccolith morphology is crucial for understanding the marine carbon cycle and the paleoclimatic reconstruction.This paper reviews the application of coccolith morphology,introducing the continuously improved methods of the coccolith morphology parameters,especially on the indicators of coccolith calcification(including the coccolith size and thickness) in palaeoceanographic studies.