Linking the CMF model to metallogenic zoning in the east Qinling Orogen, central China

Abstract

Collisional orogens are characterised by imbricate stacking of crustal slabs. During slab stacking in a compressional regime, the underthrust slab is progressively devolatilised, metamorphosed and partially melted, resulting in extensive fluid circulation and granitic magmatism in the overriding slab. Therefore, orogenic lode deposits (L), batholithic granitoids (G), and porphyries with their associated deposits (P), are zonally arranged in the overriding slab. Fluid flow, magmatism, and mineralisation are enhanced during the transition from compression-to-extension stage (i.e. from Pmax to Tmax) due to P-decreasing and T-increasing. Fluids and magmatism gradually wane in the extension stage, due to a combination of T-decreasing and the exhausting of easy-mobilized components in the deep crust (Chen 1998). This scenario is what we term the CMF model (collision-metallogeny-fluid flow). The CMF model readily explains the zonal distribution of ore deposits and granitoids in the east Qinling Orogen, for example, in the Xiaoqinling, Xiong’er, Waifangshan and Erlangping terranes.