Regular Study Of The Lancang, Yunnan Province, The Old Factory Silver Lead Deposits

Laochang silver and lead ore of Lancang in Yunnan was located in poor county of Yunnan where the national minority live, it is the pillar industry which can promote local economy and regional economy, and bring along the adjustment of industry structure. Laochang silver and lead ore of Lancang is one of the important classical deposit of the three river mature mine zone, according to the two terms silver and lead exploring report brought by the original west south nonferrous geological exploring bureau 309 team , the accumulative metal quantity of this area: lead is 86 ten thousand ton, zinc is 33 ten thousand ton, silver is 1736 ten thousand ton, they are the deposit that have a close relationship with mine effected by volcano function, and they have a broad foreground for ore finding. Attaching importance to the second time synthesize and excavate to the martial of old mine, attaching importance to research of mature ore theory, using multiple method to develop stereoscopic ore finding, the mine area of Laochang has lots of achievement through the work of so many geological worker, scientific research unit, geological team back and forth. This work brings out the initial view. It aims at making a deeply understanding of the works achievement of people before and digesting them to better finding the mine mature ore law. Enlarging deposit margin mine finding prospect and promoting mature ore zone' finding breakthrough, there are many talks about the reason for silver, lead and copper multiply metal deposit, there are three kinds acknowledgement in summary:(1)acidity magma hot liquid deposit in the middle of Yanshan period;(2)lump sulphurs thing deposit caused by volcano;(3)multiply reasoning deposit, among which the mine in the underneath lower Carboniferous Period lava belongs to volcano spurting, the mine in the upper above Carboniferous Period and lower Pco₃²⁺ rock belongs to acidity rock magma period after hot liquid filling.The paper based on overall collection of the exploring and scientific research material in the work area and digesting achievement people made before, combing the over years work experience in mine area of myself, making mine geological feature and background as the research object to make multiply analysis and dissecting.I₁₊₂ ,I₂₇ ,and I₂₈ ore body is made as a example of I mine group , II₁ II₂ II₄II₅ II₈ ore body is made as a example of II mine group, III₁ ore body is made as a example of III mine group, thus to prove that the word structure of Chinese '入', '厂' and 'stickle' and so on such multiply ore body structure is the overlap of steep veins ore body and tardy slow slope ore body formed in early stage, the interface part of marble and lava is the good moving thoroughfare and ore forming space of deeply ore liquid. Through thick big copper ore body and granite veins which are relative with silicon clipped rock released by exploring hole to testify that volcano mechanism and deeply large fissure is good thoroughfare and ore forming space to transmit hot and ore. The above illustrate that when the ore body is product in lava and crack broken zone, the ore body structure is most in steep veins and distribute through layers. When ore body is product in vast volcano zone, the ore body is mostly slow slope layer or lens. When slow slope ore body interferes crack, then the multiply ore body in which the slow ones overlaps the steep ones is formed. The paper through the analysis to geological feature of same basic element and research to ore forming law in ore area, gathering law of ore body, old volcano mechanism's control function to ore body, control rock and ore structure, stratum rock's control to ore body, silicon clipped rock and marble in lava, ore body zone ore forming function, to bring out forecast of ore forming and ore finding suggestion; Through composite analysis to ore forming geological condition, the relationship between ore forming and rift valley structure, volcano function, acidity magma underline, stratum age and rock nature and structure, the dividing of ore forming period and ore forming stage, and the deposit forming factor analysis and building ore forming pattern, Laochang of silver and lead deposit is regarded as multiply factor deposit which is classical and having a quite near relationship with volcano ore forming function, meanwhile the composite ore finding forecast pattern and symbol aggregation of Laochang multiply metal deposit is brought out, three ore finding forecast area are divided.Elephant mountain I degree forecast area(west forecast area) Lotus mountain II degree forecast area(south forecast area) Powerful army mountain HI degree forecast(north forecast area).