Supergene Alteration of Amphibole in Suryun Kaolin Deposits: Mineralogical and morphological Studies

수륜 고령토광산에서 산출되는 각섬석의 표성 변질작용: 광물학적 및 형태적 연구

X-ray, optical and electron microscope studies exhibit that the amphiboles in anorthositic saprolite from kaolin deposits, located in Suryun-myeon, Seongju-gun, Kyungsangbuk-do, have altered under weathering conditions to smectite, mixed-layer mineral, vermiculite and goethite. In early supergene alteration stage when rock structure is still preserved, smectite occurs as initial weathering product of amphibole. Further weathering leads to the formation of mixed-layer mineral, vermiculite and goethite as indicated by XRD and SEM studies. Scanning electron microscopy studies of amphibole show that the dissolution of amphibole proceeds by selective etching at the surface along weaker zones producing distinct etch pattern, The calcic amphiboles according to electron microprobe analyses, show leaching of the most mobile elements (Mg, Ca and Fe) during alteration.