Superimposed orogenesis and metallogenesis: An example from the orogenic gold deposits in Ailaoshan gold belt, Southwest China
哀牢山造山型金成矿系统：复合造山构造演化与成矿作用初探

Ailaoshan golden belt, one of the most important Himalayan orogenic-type gold belts in China, formed during the processes of superimposed orogenesis in Sanjiang Tethys. The relationship between the processes of superimposed orogenesis and gold mineralization has been discussed in terms of the studies of tectonic setting, evolution of ore-controlling structures, timing and sequence of gold mineralization. The results show that there were three tectonic-thermal events related to gold mineralization. The early gold mineralization, occurred from 61.55Ma to 63.09Ma, corresponds the peak period of the thrust system and generation of strike-slip fault, indicates they were mainly controlled by the strongly early convergence geodynamic regime of India-Euraisa conllision. The main gold mineralization, occurred from 33.76Ma to 36.10Ma, which related to the relaxation of regional compressive stress field and corresponding to the generation of alkali-rich porphyry and booming of strike-slip faults, reveals that they were mainly controlled by the transition of geodynamic regime of India-Euraisa collision, and eastward escapation of the Tibetan Plateau, and pulsating uplift of asthenosphere. The late gold mineralization, occurred from 26.40Ma to 30.80Ma, corresponds the extension of lithosphere and the intrusion of high-K plutons which came from the depleted mantle and formed during the decompression period in internal plate, were mainly controlled by the oblique reverse rotation and rollback subduction of India Plate.