江西大余牛岭钨锡矿床特征及岩浆矿床容矿构造成矿构想

Characteristics of Niuling W-Sn Deposit and Metallogenic Conception of Host Structure of Magmatic Deposit

岩浆是地壳深部形成富含挥发分的高温熔融物,上侵冷却凝固后形成岩浆岩,其冷却时收缩形成的裂隙空间对含矿热液充填成矿具有重要意义。江西大余牛岭钨锡矿床容矿构造是由岩浆侵入变质岩中,岩浆逐渐冷凝过程中,因热胀冷缩在内部形成一些裂隙空间,越往深处,裂隙空间逐渐变大,含矿热液进入裂隙空间充填成矿。由于热胀冷缩作用,成矿岩浆矿床演化成矿过程控制着成矿物质富集。在一定面积范围S内,某一冷却面X处(即某一深度),体积缩小:ΔV_(X)=α×S×dX,矿脉延长为L,则脉幅为R=ΔV_(X)/(LdX)。

Magma is a high-temperature melt rich in volatile matter formed in the deep crust,which forms magmatic rock after upwelling,cooling and solidification,and the fissure space formed by its contraction during cooling is of great sig-nificance for ore-bearing hydrothermal filling and mineralization.The ore-hosting structure of Niuling W-Sn deposit in Dayu,Jiangxi Province is that magma intrudes into metamorphic rocks.During the process of magma gradually con-densing,some fissure spaces are formed inside due to thermal expansion and cold contraction.The deeper the fissure spaces,the larger the fissure spaces are,and the ore-bearing hydrothermal solution enters the fissure spaces to fill the mineralization.Due to thermal expansion and cold contraction,the evolution and the mineralization process of ore-forming magmatic deposits control the enrichment of ore-forming materials.In a certain area range S,at a certain cooling surface X(that is,at a certain depth),the volume is reduced:ΔV_(X)=α×S×dX,and the vein is extended to L,then the pulse amplitude is R=ΔV_(X)/(LdX).