Two layers of tephra deposits can be identified from the upper sediments in Core CSH1 and are characterized by coarser particle,higher SiO_2 and Na_2O contents and lower contents of clay minerals,volatiles,Fe_2O_3,MgO,CaO and Sr.

• 从岩芯最上部的沉积物中可识别出2层火山碎屑沉积,它们都具有沉积物粒径突然变粗、SiO2和Na2O等化合物的质量分数突然增加以及粘土矿物、挥发份、Fe2O3、MgO、CaO和Sr的质量分数迅速下降等特征。