Mesozoic tectonic-hydrothermal activity driven gold metallogenesis in Dandong area, south Liaoning: evidence from FIP.

South Liaoning province, together with south Jilin province, east Shandong province, Xiaoqinling mountain areas in Henan province, and east Hebei prov ince, are five large gold-producing areas in North China Plateform. Importa nt gold deposits in south Liaoning province are distributed in Dandong area . There are two typical and large gold deposits: Wulong gold deposit and Si daogou gold deposit respectively. Concerning with the gold mineralization e poch in this area, geologists hold two popular and different views. Some ge ologists favour two gold mineralization epochs: Proterozoic and Mesozoic mi nerarization epoch, whereas others prefer one mineralization epoch, that is Mesozoic minearalization epoch. The authors working on FIP reveal that (1) the trapping time for rock-forming fluid from local granite is the same as the trapping time of ore-forming fluid from the auriferous quartz veins in Wulong and Sidaogou gold deposits; (2) the rock-forming fluid of granite a nd the ore-forming fluid of gold deposits are all trapped under the same re gional stress field; (3) the rock-forming fluid of granite and the ore-form ing fluid of gold deposits can be related to the same Mesozoic tectonic-hyd rothermal activity in Dandong area. These data are in good agreement with t he one-mineralization epoch model: Mesozcic gold metallogenesis. In additio n, this study also shows that the FIP method is a new hut very efficient an d helpful one in the research field of rock-forming and ore-forming process es.