Regional Volcanic Bodies And Their Ore-controlling Characteristics Of The Trees Ditch

The project workspace is located in the south-central of the greater hingganmountain, and belong to a part of the Inner Mongolia-Khingan slot which is betweenSiberia plate and Sino-Korean plate. The major tectonic activities in this area areVariscan structural movement and Yanshanian structural movement. A large-scalevolcanic movement and mineralization occured frequently in this region by theinfluence of the tectonic activity, and at the same time there were many different typesof volcanic edifices forming in this zone.This paper mainly through a detailed field geological mapping and a depthdissection to the related data classified the volcanic edifices in this region into fourtypes according to their different characteristics:①caldera;②volcanic dome;○3strato volcano, and summarized their respective characteristics. Based on studying thevolcanic edifices’ ore-controlling behaviors, this paper also classified these behaviorsinto such types: volcanogenic-eruption ore deposits, pneumato hydrothermal oredeposits formed in the late of volcano eruptible period and the ore-controllingdeposits of ancient volcanic edifices. The volcanogenic-eruption ore deposits can bedivided into volcanogenic-sedimentary ore deposits and volcanic-magmatic oredeposits. And the pneumato-hydrothermal ore deposits formed in the late can bedivided into the ore deposit related to the deep magma source and the ore depositsabout secondary volcanic rock.Due to the huge differences among these volcanic edifices’ factors in controllingdifferent types of ore deposits, this paper summarized some following rules in thefurther studies:①the volcanogenic-sedimentary ore deposits, are mainly controlledby the crater subsided region, their ore-bodies are yielded in bedded;②thevolcanic-magmatic ore deposits, are mainly affected by the volcanic edifices whichhave volcanic conduit, their ore bodies are bell shaped or columnar etc.;③thepneumato-hydrothermal ore deposits formed in the late of volcano eruptible periodoriginated in volcanic center (crater-near crater facies), and are controlled by these volcanic edifices such as volcanic conduit, volcanic uplift, explosion-breccia and thecracks around the crater.At last, according to the south—central of the greater hinggan mountain’sgeological background and its mineralization background, this paper argues thatsearching the ore deposits controlled by volcanic edifices need to do the followingfive key measures:①finding out the relation between the tectonic setting andmineralization;②finding out the relation between the basement structure ofvolcanic basin and mineralization;③understanding the ore-bearing properties ofvolcanic edifices and volcanic rocks;④finding out the distribution of hypabyssalrock related to volcanic edifices;⑤finding out the relation between the fault relatedto volcanism and the volcanic edifices.