Long-term oxidation behavior of Zr48Cu36Al8Ag8 BMG under atmospheric conditions at 600 K was investigated using in-situ X-ray diffraction analysis. Two oxide zones develop: an outer oxide zone (OOZ), consisting of a stratified distribution of CuOx, Ag, and ZrO2, and an inner oxide zone (IOZ) consisting of tetragonal ZrO2 showing Cu-enriched lines inclined to the surface. The stratified microstructure in the OOZ and the Cu enrichments in the IOZ are ascribed to micro-cracks resulting from the compressive stresses induced by ZrO2 formation. Segregation of noble elements towards these oxidation-generated free surfaces "repairs" the micro-cracks and can consistently explain the microstructural features.