Geochemical study on anatexis of leucoleptites in Fuping Group of Xiaojue area, Pingshan County, Hebei Province

Anatexis resulted in the formation of leucosomes of various shapes and sizes in leucoleptites of Neoarchaean Fuping Group. The anatectic derivatives have lower REE content and HFS elements than their melting parent rocks. In most cases, however, they show similar element distribution patterns. The derivatives formed at the early stage of anatexis are different from the parent rocks in concentrations and distribution patterns of elements. With the development of anatexis, the difference between the derivatives and the parent rocks in Nd isotopic composition became smaller and smaller until approaching to disappearance at last. The accessory minerals, especially zircon and apatite, played an important role in the variation of elements and Nd isotopic compositions of the anatectic derivatives.