Tree rings and seasonal sedimentary deposits called varves can be counted to determine absolute age.

可以树木的轮和被称为纹泥的季节性沉积物进行计数来确龄。

The variation of varve thickness may show a decrease of sediment flux during the Little Ice Age, and an increase of sediment flux after 1960s.

但纹层厚度的变化可能揭示出小冰期沉积通量的减少和上个世纪六十代之后沉积通量的增加。