Progress has been made in the study of the genetic relationship between lead-zinc deposits and molybdenum deposits in the southern margin of North China where Guangzhou geochemistry is located
The southern margin of North China craton is famous for its abundant Mo resources and is the largest Mo ore belt in the world. With the deepening of geological prospecting, a large number of lead-zinc deposits have been discovered in the southern margin of North China in the past few decades, which makes this area an important source of lead and zinc resources in North China (figure 1). There are some arguments about the genetic relationship between these lead-zinc deposits and molybdenum deposits. Some scholars think that lead-zinc deposits are the products of the far end of porphyry Mo deposits, which are magmatic and hydrothermal products of the same stage, while the other part of the study thinks that these lead-zinc deposits are formed under the continental collision mechanism, and the ore-forming fluids come from the metamorphism and dehydration of the strata. There are also a small number of views that these lead-zinc deposits are MVT or SEDEX deposits. Through the previous investigation, it is found that there are a large number of lead-zinc deposits in the Fudan mine concentration area, which are distributed around Donggou Mo ore (Fig. 2). Among them, Wang Ping Xigou lead-zinc deposit is the largest lead-zinc deposit in the area, and its metallogenic age is consistent with that of Donggou Mo deposit. Based on this, Zhao Taiping, a researcher in the Laboratory of Mineralogy and mineralization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, and Jinchang, a Ph.D. graduate student, were selected as the research objects to explore the genetic relationship between lead-zinc deposits and molybdenum deposits. Based on the field and microscopic observation, it is identified that the mineralization of Wang Ping Xigou lead-zinc deposit can be divided into three stages, while the mineralization of Donggou Mo deposit can be divided into four stages. Based on the microregional geochemistry of sulfides in the second stage of Wang Ping Xigou and the second and third stages of Donggou, it is found that the trace elements from Donggou Molybdenum Mine to Wang Ping Xigou lead-Zinc Mine have the characteristics of linear distribution. It is consistent with the evolution characteristics from porphyry to shallow cryogenic hydrothermal system (Fig. 3). In addition, the sulfides of the two deposits have similar Pb isotopic characteristics to Donggou porphyry (Fig. 4). Combined with the similar metallogenic ages of the two deposits, the researchers believe that the Xigou lead-zinc deposit in Wang Ping is the product of the far end of the Donggou porphyry Mo deposit, and the two deposits are a metallogenic system, which provides some good ideas for the future prospecting work. Many lead-zinc deposits (Shagou, Hapinggou and Tieluping, etc.) in this area are distributed in discrete form. So far, no porphyry Mo deposits have been found around them, so it is inferred that there is the potential of porphyry Mo deposits around them. On the other hand, the periphery of some large or super-large porphyry Mo deposits (such as Laimengou and Yuchiling, etc.) may be a favorable target area for finding Pb-Zn deposits in the future.
