Research On The Ore-Controlling Role Of Structure In The Middle-North Section Of The Taihang Mountains

The middle-north section of Taihang Mountains and is mainly consisted of the Fuping uplift its periphery on the regional tectonics and is located in Pingshan-Fuping-Laiyuan area in Hebei province. Due to geological metallogenic environment since the Yanshan movement, such as complex and diverse structure, strong magmatic activity, numerous gold-silver-lead-zinc-copper polymetallic ore deposit, and obvious structural ore-control and rock-control, etc, it has been a natural laboratory and practice base for geologists.Supported by the research on the mineralization of Mapeng area in Fuping mantle branch structure(NO:40872137, national natural science foundation) and the research on metallogenic regularity of Mujicun copper(molybdenum) deposit in Hebei province and antimony(gold) deposit in the middle part of Hunan province(NO:20109901, national crisis mines resources prospecting project), this paper mainly studied diagenesis and mineralization of structural control ling by the theory of Mantle branch structure, in order to summarize metallogenic regularity, establish metallogenic model, and guide the further geological prospecting work in the middle-north section of Taihang Mountains.This paper summarized the characteristics of regional geological structure and its evolution in the middle-north section of Taihang Mountains, and briefly introduced the multiple evolution of mantle plume and the theory of mantle branch structure as well(the mantle branch is the third grade of structural units during multiple evolution of mantle plume). Combined with regional geological, geophysical, geochemical and remote sensing geological data, it attributed its regional geological evolution since the Mesozoic to the evolution stage of Fuping mantle branch structure, divided the area into three parts of metamorphic core complex zone, detachment zone and the upper sedimentary cover zone and taked 120-140 Ma as the its activity-peak by the view of mantle branch structure.This paper also studied the regional metallogenic material sources and the temporal-spatial distribution of diagenesis and metallogenesis. Through testing and analyzing(some data from the previous results) sulfur, lead, hydrogen, oxygen, carbon, silicon and the helium and argon isotopic data from about 500 pieces of ore-rock samples in more than 20 gold and silver polymetallic deposits, it showed that the regional ore-forming materials were mainly from the deep earth and partly from the crust materials, the ore-forming fluids were mainly from the magmatic water and partly from the atmosphere water, the main epoch of diagenesis and mineralization was roughly 120-140 Ma and was consistent with the main process of mantle branch structure in the Yanshan movement, and its diagenesis and metallogenesis was closely related to the deep earth processes.From the view of mantle branch structure, this paper focused on the anatomy of typical structural ore-control features of three types deposits with Shihu gold deposit in the core zone, Mujicun copper(molybdenum) deposit near the detachment zone and Zhijiadi silver(lead-zinc) deposit in the cover zone, and established the corresponding metallogenic models. Combined with regional geological characteristics, it considered that the distribution of regional rock masses and deposits were strictly constrained by all levels of ore-control structures of Fuping mantle branch structure in space, summarized the regional tectonic ore-forming and regularity of structural ore-control, and pointed out the focus zones of regional geological prospecting in the further by contrast and analysis of regional similar deposits. In a word, The evolution of Fuping mantle branch structure was not only driving force for regional tectonic movement, the magmatic activity and the mineralization, and also controlled their temporal-spatial distribution and relatively evolution since middle-late periods of the Mesozoic.