| Dazhuangzi gold ore field is located in the southwest of the Jiaoxibei gold metallogenic area. Since the shallow gold mine resources of the ore field have been exploiting continuously, the existing resources can not meet the development of enterprises. It is urgent to enhance the reserves. The altered rock type in the ore field is larger than the quartz vein type, high degree of development, and the development of quartz vein type ore bodies are also only limited in shallow, with low degree of attention and a few studies.This paper selected Dazhuangzi gold field as the research object. Ore field tectonic research methods as means of study. The study focus on the Ore field structural analysis,proved the ore-controlling structure regularity, and establish metallogenic model of the Ore field to make prospecting prediction and delineate the prospecting targets.This paper based on collecting, sorting and analyzing the existing research data in the work area, and Fixed-point observation in detail, measured typical structures profile and sampled scientifically. It combined with macroscopic and microscopic geological observation, summarizes the ore field geological characteristics. By analyzing ore field tectonic stress reveals ore body preservative law. Combine all the information to discuss the ore field tectonic ore-controlling model.The above studies show the following understanding:(1) Dazhuangzi gold ore field is strictly controlled by the fault structures. And there are main three group faults: NW, NNE and NEE. The NNE trending structures are mainly mineralization faults, and also some are post-mineralization; The NW-trending structure faults are mainly post-mineralization and few mineralization.(2) The tectonic stress field analysis shows the maximum principal stress direction of ore field is NE-SW and NW-SE direction is stretch. The main trends of ore-controlling faults in Dazhuangzi quartz vein gold type deposits are NNE, NE and NEE, whole belong to brittle-ductile shear zone controlling mode. The secondary faults space controlled by Dazhuangzi fault is the best of orebody enrichment area. The overall is "X" shape, and the distribution of the ore bodies are controlled by shear grid and appear almost equally spaced arrangement characteristics and echelon arrangement rule.(3) The quartz vein type mineralization is mainly developed in the footwall of Dazhuangzi fault, the spatial distance between them is similar, but there is notmineralization in the interval. So the relationship between them is not primary-slave relation, but is the same class ore-controlling structure.(4) Ore field structure analysis shows that tectonic metallogenic fault stretch in NW-SE direction. Combining previous research that the ore field formed in about 110 Ma of the early cretaceous, to speculate that structure occurred in continental extension background.Fracture tectonic activities provide fluid circulation channel and mineral precipitation space, control the metallogenic environment for low temperature condition, and magmatic water and atmospheric water involved in fluid, which reflect structure in deep and shallow connected. Previous studies of sulfur source is the mantle sources, also provide evidence of deep structure connected. Mafic dyke occurs within the ore field also reflects the deep tectonic activity.(5) Faults, phyllic, and potassic alteration, lithology interface are important symbols of prospecting. The Houjia to Hongshan area in northeast of Dazhuangzi gold ore field is important prospecting target. |
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