Post-deposition transformation in banded sphalerite, MVT-type deposits, Upper Silesia, Poland

摘要

Banded sphalerite may be a subject of post-formation transformations related mainly to leaching of Fe while Zn and S content remain unchanged. These transformations are controlled directly by micro-porosity and micropermeability (microfractures) with sub-μm size. The system of microfracures and micro-porosity may control re-introduction of iron into sphalerite obliterating age dating by remnant magnetization technique. This may rely on superposition of original magnetisation vector acquired during precipitation of ZnS on later magnetisation vector acquired during re-itroduction of iron into ZnS through micrfractures and microporosity.