Occurrence of Au in mantle minerals and its possible model of transformation: Example from peridotitic xenoliths in North China

Twenty-one peridotite xenoliths were collected in North China several regions. Their contents of CaO, trace elements, REE and Au were determined. Relationship between gold and CaO contents for the 21 xenoliths suggests that the Au content may be related to mantle evolution and melting degree of mantle, showing that the Au may be occurred in clinopyroxen. However, the Au in peridotite xenoliths was hosted in sulfides when the xenoliths were affected by later replacement of mantle fluid. The transformation of Au from the host mineral, clinopyroxene to incorporation in sulfide was carried out on the basis of the primary Au in the peridotite xenoliths.