柿竹园-野鸡尾钨锡钼铋多金属矿床流体包裹体初步研究

STUDY OF FLUID INCLUSIONS OF THE SHIZHUYUAN-YEJIWEI W-Sn-Mo-Bi-POLYMETALLIC DEPOSIT IN SOUTHERN HUNAN

该矿床石英中流体包裹体的均一温度频率直方图具明显的塔式结构。柿竹园和野鸡尾矿段主要成矿阶段的温度下限分别为230—300℃和220—240℃(经压力校正)。这两个矿段流体包裹体、盐度频率直方图亦非常相似,并均具较低的数值,说明两地段成矿溶液特征相似并且均不成。计算结果表明,矿床成矿流体密度和压力均较低。流体低压力值与矿床就位深度较浅(小于1—2kin)的地质证据相一致。成矿流体密度等值线图上的密度高均分布于花岗岩和花岗斑岩或石英斑岩和花岗岩与矽卡岩和大理岩具复杂接触关系的地段。而这种复杂接触地段的矿化强度通常较高。

Histograms for homogenization temperature of fluid inclusions in this deposit show an apparent lower structure. The lower limits of temperature of the major metallogenic stage in the Shizhuyuan and the Yejiwei ore sections are 230-300℃ and 220-240℃ (corrected for pressure) respectively.The two ore sections have similar histograms for salinity of fluid inclusions, both characterized by fairly lower salinity values. This suggests that their ore-forming solutions share similar characteristics.Calculation indicates that the ore-forming fluids of the deposit have lower density and pressure values. Such lower pressure values coincide with the geological evidence that the emplacement depth of the deposit does not exceed 1-2 km.Isodensity contour map of fluid inclusions in quartz hows that the density heads are situated in complicated contacts of granite and granitic porphyry or quartz orphyry and granitic pophyry with marble and skarn. Along these complicated contacts the intensity of ineralization is usually high.