| The1001Highland Pb-Zn polymetallic deposit is located within volcanic rock beltbetween border of south margin of the Erguna mass and Grent Xing’an fault zone(volcanic rock zone). Tectonic activity is frequent and magmatic activity is intensity in thestudy area. Therefore, strata is only exposed in the southwestern part of study area, andvolcanic rocks well developed and occurred as complexity of magma-fault-volcano.The exposed stratum in the study area are composed of the Neoproterozoic-LowerCambrian Wolegen rock group complex (Pt3-∈1), Jixianggou rock group (Pt3-∈1) andDawangzi rock group (Pt3-∈1), Mesozoic Upper Jurassic Baiyingaolao group (j3b) andLower Cretaceous Longjiang group (K1l), Guanghua group (K1gn) and Ganhe group (K1g),as well as Cenozoic Neogene Holocene developed along gully.The intrusive rocks are well distributed in the area, and rock bodies occurred asirregular shape, lentoid shape. The rock occurred as stock, boss shape develoed in thenorthern and middle part of area, which distributed as NE-and EW-trending andfromation age is the Early Cambrian, Late Jurassic and Early Cretaceous. The volcanicrocks is well developed in the area and composed of a series of intermediate–acidic,intermediate, acid, intermediate-basic rock formed from the Late Jurassic and EarlyCretaceous, which experienced five volcanic eruption periods and constitute three eruptioncycles, including Baiyingaolao stage, Longjiang stage, Guanghua stage and Ganhe stage. The vein rocks is mainly composed of diorite vein, porphyry diorite vein, porphyry granitevein, granite aplite vein and quartz vein, and so on. These veins controlled by tectonics aremainly occurred as NE-and NW-trending, with minor EW-trending, and0.7-1km inlength and0.5-0.7km in width.Magmatic activity is frequent in the Early Paleozoic-Late Mesozoic, especially in theLate Mesozoic, which formed large area of volcanic rock zone with intruding of granite.The magmatic activity is associated with metallogenesis, especially volcanic activity inthe Late Jurassic-Early Cretaceous is closely associated with metallogenesis and formedimportant ore-forming control condition.In conclusion, frequently magmatic activity in the area is associated withmetallogenesis. Gold-bearing quartz vein with high abundance value of gold developed inthe Early Paleozoic-Late Mesozoic granite, and Mesozoic volcanic rock with highabundance value of nonferrous metal elements, which provided mineral source body andsource bed for regional ore-forming. The each period of magmatic activity also providedheat source for migration and enrichment of metallogenic elements, and formed magmaticrock condition for metallogenesis.The author considered that orebodies from the1001highland Pb-Zn metallic depositis vein in shape and hosted in the Early Cretaceous Longjiang stage (K1l) stratifiedvolcanic edifice eruption facies intermediate-acid lava. Wall rock alteration is dominatedby epidotization, chloritization, carbonatization, pyritization, sericitization andkaolinization, and epidotization, chloritization and pyritization is closely associated withmetallogenesis. The ore mineralogy contains sphalerite, galena, magnetite, pyrrhotite,pyrite, chalcopyrite and covellite, and are mainly composed of sphalerite and galenahosted by altering andesite and dacite. The ore grade is relatively lower and range ofvariation is stable.The vapor-water hydrothermal from late period of volcano-magmatic activityaccessed to wall rock along heat transfer structure, and activated metallogenic elementswithin wall rock, which combined with metallogenic elements from deep and migrated toprofitable warm-pressing condition and position of ore-bearing structure and concentrated to be mineralization and ore-body. The metallogenic age is the Early Cretacesou, andgenetic type is belong to volcanic hydrothermal type polymetallic deposit formed bymultiple periods of tectonic-magmatic activity. |
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