次生萤石的特征及其成因

本文探讨了次生萤石的成因。由于成矿后的断裂活动,使原生萤石脉受压破碎,形成了空洞。细末状萤石在地下水作用下形成胶体溶液搬运、沉淀和再结晶。另外,随着成矿后构造断裂而来的热液,引起萤石的新的溶解和结晶。

FEATURES AND ORIGIN OF SECONDARY FLUORITE

Large quantities of grape- and Stalactite-shaped white, light-green and purple crystal aggregates of secondary fluorite growing on the original crushed fluorite breccia were found in the caves along the structural fractures of the fluorite deposit in Ziyuan County, Guangxi. Bigger aggregates are perfectly crystallized.In regard to its origin, it is proposed that the caves were first formed in such a way that the primary fluorite veins were crushed because of post-ore faulting, where fine-grained fluorite was transported in the form of colloidal solution in ground water, then precipitated and recrystallized. Finally, under the action of hydrothermal solutions which found way upwards along the postore structural fractures, the fluorite (CaF_2) was redissolved and recrystalllzed, producing the secondary fluorite.