河北平山晚太古代阜平群中主要变质岩类及其深熔产物的稀土地球化学初步研究

Preliminary Study on the REE Geochemistry of Some Metamorphic Rock Types of the Late Archean Fuping Group and Their Anatectic Derivatives in the Pingshan Area, Hebei Province, China

河北平山小觉地区晚太古代阜平群含有三种主要表壳岩性质的变质岩类，即钾长浅粒岩类，黑云变粒岩－片麻岩类和角闪质岩石类。它们所经历的初期深熔作用产物，其岩石化学成分分别与钾长花岗岩，奥长花岗岩和花岗闪长岩相当，并在很大程度上继承了原岩（母岩）的总体岩石化学特征。可能由于深熔产物中富含稀土的一些副矿物含量的降低，它们的稀土总量都不同程度地较原岩为低，但两者的稀土分布模式却很相似，这从另一角度说明了它们的成因关系。

The Late Archaean Fuping Group of the Xiaojue region in Pingshan County, Hebei Province contains three main metamorphic rock types, i.e. K felspar leucoleptite, semipelitic biotite leptite and biotite gneiss, and hornblendic rocks. Their anatectic derivatives formed during the initial stage of anatexis are petrochemically of K rich granitic, granodioritic and trondhjemitic compositions respectively, and in general have inherited the main petrochemical features from their respective parent rock types.Probably due to the fact that they contain less REE rich accessory minerals as compared with their parent rocks, thus the anatectic derivatives are in general lower in ΣREE content. But both the derivatives and their parent rocks have similar REE patterns, which serves as an additional indication to the genetic relashionship between them.