A mineral controlled fault system that controls the metallogenic zone

According to the results of field observation and systematic structural-mineral combination mapping, and the different mechanical properties and supporting relationships reflected by various structural traces, the structural-alteration-mineralization activities can be divided into three phases and seven stages (Fan Yongxiang et al., 1993).

The structural properties of ore-controlling faults and the metallogenic constraints of their pre-metallogenic activities are mainly manifested in the following aspects: The NEE trending faults are compressive and compression-torsional before metallogenic and are not conducive to vein filling, and only during the metallogenic period are superimposed shear, and after composite transformation, especially local extension, can they be transformed into favorable conditions for vein filling. Therefore, the gold-bearing quartz veins controlled by this type of fault expand and contract greatly, and the controlled industrial ore body is often intermittently distributed.

The faults trending in the NNE trend are mainly torsional before metallogenic period, and when superimposed shear activity occurs during the metallogenic period, conjugate shear and micro-tension fractures often occur in the fracture zone, resulting in fine vein filling and chain guessing chain transport dissemination metasomatization of the gold-bearing ore liquid, forming a sulfide network vein-type ore body in the fracture zone, and the mineralization continuity and stability are good. The ore-bearing faults formed before mineralization, whether they are compressive-torsional or torsional, have great extension and depth, which is of great significance for evaluating the deep prospect of the mining area.

After metallogenic periodicity, the main ore-bearing faults in the ore field have experienced at least two or more tectonic movements, and they often cut through the veins, and the dislocation of the veins is rare, and the dislocation of the spike vein is generally not large. To trace the ore body that has been miscut by faults and veins after mineralization, it is necessary to pay attention to judging the relative miscutting direction, and determine the tracking direction according to its tectonic properties.

The general trend of the distribution of copper polymetallic mineralization concentration areas is a north-east-trending belt, east-west rows, and north-west bands, forming a panicle-tectonic belt. Some of them occur in secondary structural blocks intersected by multiple groups of linear structures to form mineralization-structural blocks, and some are located on the linear structural "junctions" of the convergence of linear structures of the Duo Poor Nationality Formation, forming mineralization-structural junctions. The main parts of copper polymetallic deposits on the remote sensing structure are: multiple groups of linear structural intersection points, such as the Budunhua copper ore structure with two groups of fault structures (Fig. 3-11), one group of north-south trending fault structures and one group of north-west trending fault structures; the edge of the secondary structural block formed by multiple groups of linear structures; Linear structures in a certain direction, such as the Haobu high-copper-lead-zinc deposit (Fig. 3-12), have a group of north-north-east-trending fault structures to control the distribution of ore bodies. middle part of the annular structure; The inner and outer sides of the outer ring margin of the annular structure, such as the ore body of the Duobaoshan copper-molybdenum deposit, are distributed on the outer margin of the annular structure (Fig. 3-13); For example, the ore body of the copper-molybdenum deposit in Wunugetutshan is distributed in the middle of the volcanic annular structure, and there are multiple sub-minimal volcanic annular structures combined with each other to form a volcanic assemblage ore control structure (Fig. 3-14), the ore body is controlled by the volcanic annular structure, and the subvolcanic rock is very developed.

Figure 3-11 Diagram of the relationship between the structure and mineralization of the Butun copper deposit.

Yanshan granite.

Yanshan granite porphyry.

Figure 3-12 Relationship between structure and mineralization of high-copper-lead-zinc deposits in Haobu.

Figure 3-13 Relationship between the structure and mineralization of the copper-molybdenum deposit in Duobaoshan.

Figure 3-14 Relationship between the structure and mineralization of the copper-molybdenum deposit in Wunugetu.

The tectonic pattern of the metallogenic belt composed of NE and east-west tectonic belts is the main ore conduction structure, and the NE and SE tectonic structures and their small tectonic patterns play an important role in the positioning of ore deposits and ore bodies. In terms of the overall tectonic trend, the regional line-ring tectonic zone controls the distribution of the mineralized tectonic zone, the structural blocks and tectonic junctions control the occurrence of the mineralized concentration area, and the linear structure, linear structural intersection points and annular tectonic margin interface determine the positioning of the deposit, which constitutes the regional ore-controlling structural characteristics of the metallogenic belt (Fig. 3-15).

Figure 3-15 Relationship between regional (remote sensing) structure and polymetallic mineralization.

According to Zhi Qihan et al., 1996, adapted).

a—Naoniushan copper deposit; b—Lianhuashan copper deposit, Changchunling lead-zinc deposit; c—Menn Tolgoi silver-lead deposit; d—Shichang Wendur lead-zinc-silver deposit; e—Tabulegi Copper Deposit; f—Laodaogou lead-zinc-silver deposit; h—Shuiquangou copper-lead deposit; i—Youloushan lead-zinc-silver deposit. 1—gravitational magnetic inference fault; 2-linear structure; 3-annular structure; 4—normal volcanic structure; 5—negative phase volcanic structure; 6—copper deposits; 7—lead-zinc deposits; 8—silver-lead deposits; 9—Lead-zinc-silver deposits.

The Jinjiyan gold deposit is located in the northern margin of the middle section of the Jiangzhuanfu-Shaoshen fault and the composite part of the east-west fault zone and the north-east-trending fault zone in the southern margin of the eastern section of the Jinhua Beishan arc structural belt. F1 in the mine

The F3 NE-trending fault structure directly controls the production of subvolcanic rocks, which are most closely related to mineralization, and also controls the distribution of ore bodies, mineralized zones and mineralized anomalies. They are not only ore-conducting structures, but also ore-bearing structures. The gold ore body occurs in fractures in and near the fracture zone of silicification fracture zone.