南极菲尔德斯半岛湖泊沉积物的稀土地球化学

REE GEOCHEMISTRY OF LACUSTRINE DEPOSIT ON THE FILDES PENINSULA

本文研究了燕鸥湖、西湖和基太湖湖泊沉积物的稀土地球化学。这些湖泊沉积物的稀土分布模式与菲尔德斯半岛第三纪火山岩非常相似，它们的物质来源是菲尔德斯半岛岛弧火山岩。湖泊沉积相与冰碛层稀土模式的差异，反映了它们经历的化学风化程度不同、粘土含量不同。Ｃｅ异常意味着每个湖泊沉积旋回结束的阶段气候是比较干燥的。湖泊沉积物的稀土含量和分布模式变化小，也意味着在中晚更新世时气候是比较干燥的。

The REE geochemistry of lacustrine deposits on the Fildes Peninsula has been investigated in this paper,Their REE patterns are similar very much to those of Tertiary volcanic rocks on the Fildes Peninsula. So the lacustrine deposits are derived from island arc volcanic rocks. The difference of REE compositions between lacustrine face deposits and drift sheet shows that they underwent chemical wethering on different degree and contained clay with different content. Ce anomaly suggests that the cycle of lacustrine deposit evolves from weter environment to drier one. The contents and compositions of REE are unvariable, indicating that the weather was relatively dry in middle and late Holocene.