云南镇沅金矿煌斑岩蚀变过程中元素活动规律

THE REGULARITIES OF ELEMENT ACTIVITIES IN ALTERATION OF LAMPROPHYRES IN ZHENYUAN GOLD DEPOSITS,YUNNAN PROVINCE

广泛分布于云南镇沅金矿、与金矿化在时间上、空间上密切共生的煌斑岩普遍遭受不同程度的蚀变。根据岩石的蚀变相对强弱，本区煌斑岩可分成新鲜（弱蚀变）、蚀变两种。质量平衡方程对蚀变过程中元素活动规律的计算结果表明，引起本区煌斑岩蚀变的流体为一种含过渡元素、亲石元素、挥发性元素和亲硫元素（或成矿元素）的富硅、铝碱性流体，这种流体可能是本区煌斑岩岩浆演化到晚期分异出来的产物。

Lamprophyres, which widely distribute over the the Zhenyuan gold deposits,Yunnan province, and are temporally and spatially related to gold mineralization,have undergone different degrees of alteration.Lamprophyres in the orefield may be divided into tow groups fresh (weak alteration)and altered.The calculation results of Mass Balance Equation for the regularities of element antivities in processes of lamprophyric alteration showed that the fluids which gave rise to lamprophyric alteration are alkali fluids which are enriched Si,Al relatively and contain transition elements lithophile elements,volatile elements and chalcophile elements (or ore-forming elements).We considered that those fluids were products of crystallization differentiation of lamprophyric magmas.