Syn-mineralization Uplifting and Exhumation of Porphyry Systems in China: Evidence from Fluid Inclusion Data

In order to understand how the metallogenic process of porphyry deposit specifically and directly respond to regional uplifting and exhumation, we compiled previous fluid inclusion data of 32 porphyry deposits in China by recalculating the fluid trapping depths and trapping depth reduction magnitude from early to late mineralization stage veins. The data reveal that the average trapping pressure ratio (Ave TPE/TPL) between early- and late-stage veins of the these deposits are 1.2-18.4, mainly in the range of 1.35-5.83, with average trapping pressure reduction (1-Ave TPL/TPE) from early- to late- stage veins are 17%-95%, and mainly in the range of 25%-83%. The fluid trapping pressure based mineralization depths most of the porphyry deposits in China had decreased from early to late vein stages by at least 450 m (900-5800 m predominant), or greater than 950 m when take the average depth reduction value, which is greater than the current gap between early- and late- stage veins of each deposit. We propose that the apparently greater mineralization depth reduction magnitude than the current elevation gaps between early and late veins are likely a consequence of syn-mineralization uplifting and exhumation process that often occurs in porphyry systems.