The Geological Features Of Silver-Lead-Zinc Mineralization District And Target Study Of Moruogeqin, Inner Mongolia

The study area, Moruogeqin Ag-Pb-Zn mineralized belt, is a new polymetallic mineralized zone discovered in Moruogeqin district, eastern Inner Mongolia. Regional geological setting, major ore-controlling factors, and the extracting technology of ore guide of the Moruogeqin mineralized belt were studied in this work. Further, a multivariate prognostic model based on multidimensional framework was found. Moreover, based on these work, the ore-forming prospect and ore-finding potential of the Moruogeqin mineralized belt were evaluated.Previous geological, geophysical, geochemical, remote sensing and mineral resources data of the Moruogeqin district were collected and analyzed systematically. According to the active continent marginal trench-arc-basin theory, combining with the spatial and temporal evolutionary history of regional tectonic setting, the ore-finding orientation was put forward in the study area. Geological mapping at middle- and large-scale, geochemical and geophysical survey were carried out in this study. On the aspect of geological mapping, 109.48km2 at 1:50,000, 24km2 at 1:10,000 and 2.4km2 at 1:2000 were implemented. On the aspect of geochemical survey, debris survey in the Moruogeqin district was carried out. On the aspect of geophysical survey, ground high-precise magnetic prospecting, large-power induced polarization prospecting, high-density electrical method and EH4 survey were being done. In addition, a new geological instrument used for alteration mineral mapping, PIMA, was be used in Moruogeqin district firstly. Consequently, the information of alteration minerals in Moruogeqin Ag-Pb-Zn mineralized belt was comprehensively gathered.A few strong sericite and limonite alteration zones, which developed both in Ordovician and Devonian strata, were discovered during the detail geological mapping, and it is distributed along NNE-trending fault obviously. The mapping at 1:2000-scale exactly determined the geological characteristics and distribution of ore body in Maxibatushan district as well as made process in rock types and distribution of alteration zone. Considerable study has been done for scale of sampling medium in geochemical exploration by cuttings, then medium of -4~+20 mesh were selected as sample object in the study area. The results show that extracts abnormality has been strongly raised by adopting these samples. There are 9 elements overlying geochemical abnormal zones outlined in scope of 93km2, most of those with character of multi-element, large size and high intensity, and the distribution of mainly mineralization elements well-zoned. Three magnetic anomaly zones were outlined in scope of 30km2 by magnetic surveying. Nine polarizabilitic anomaly belts were outlined by using induced polarization method, including five low-resistivity and high-polarizabilitic anomalous areas; two moderate-resistivitic and moderate- polarizabilitic anomalous areas, and two high-resistivitic, medorate-polarizabilitic anomalous areas. There are four low-resistivitic, high-polarizabilitic anomalous areas which arranged like strings of beads in Buhadashan prospect. There are two moderate-high-resistivitic and moderate-polarizabilitic anomalous areas which located at excontact embayment of Indosinian intrusions in Maxibatushan prospect. Further high-density electrical survey and EH4 survey both indicated visible anomaly. Distribution of strongly sericite altered zone, chlorite altered zone, montmorillonitized zone and kaolinized zone within study area were defined by PIMA survey, and the declining orientation of temperature at which altered mineral formed were pointed out. The multivariate prognostic model, with various ore-finding guides and various mineralized units types as independent variable 2-dimensional axis, according to the expert's experience model, proposed the evaluation of the prospecting district. Combining detailed field work with in-door analyses, six prospecting area were determined in Moruogeqin Ag-Pb-Zn mineralized belt, which can be classified as A, B and C three types. Buhadashan and Maxibatushan prospecting area belong to the A type, and are the best area have mineralization potential. Moruogeqin Cu-Ag mineralized spot and Wulan aobao prospecting areas belong to the B type, and are the better areas which have mineralization potential. Sharburuotunuor and Aerbulang prospecting area belong to the C type which has the potential area. The major ore-controlling factors in Moruogeqin district are the early Yanshanian magmatic rocks and contemporaneous faults. The ore-forming materials derived from the early Yanshanian intrusions, and the contemporaneous faults are the transporting and deposition space for ore-forming fluids.