Thoughts on the Jiaodong gold province of China: Towards a tectonic model

The Jiaodong gold province is situated in the eastern Sino-Korean Platform within the so-called Jiaoliao Uplift. The basement rocks are Archaean and Proterozoic metamorphic rocks. Mesozoic sedimentary and volcanic cover occur within extensional basins. Intrusive rocks are dominated by Mesozoic granitoid, with intermediate-acid and basic dyke swarms. The structures form an E-W-trending anticlinorium in the basement complex, and large-scale NE-SW- and NNE-SSW-trending fault zones of Mesozoic age. The gold mineralization is associated with the Mesozoic faults and related secondary fractures in the granites or granite-basement contacts. The mineralization types are quartz-vein type and wall-rock alteration type. Wall-rock alteration is very well developed around the ore zones. Alteration minerals include quartz, sericite (and fuchsite), pyrite, calcite, chlorite, hematite, rutile and graphite. The ore assemblage is uniform in all deposits, including pyrite, chalcopyrite, galena, sphalerite, arsenopyrite, pyrrhotite, gold, electrum, hessite, petzite, magnetite, molybdenite, tetrahedrite and wolframite. Mesozoic collision and subduction between the South China and North China continental blocks contributed to formation of the Mesozoic granitoid intrusions. The granitic magma is considered to be derived from partial melting of the crust through underplating processes. Gold was remobilised from basement rocks and deposited in fracture zones by the high-temperature fluids associated with these processes.