The cementation of Upper Silurian biohermal rudstones and bedded crinoidal grainstones on Gotland, has been investigated with eathodoluminescence microscopy. The cement stratigraphy includes early marine cement succeeded by clear calcite cements indicating transition from oxidizing to increasingly reducing pore water conditions. The distribution of cement generations shows a systematic variation which indicates preferential penetration of the coarse-grained biohermal rocks by oxidizing meteoric water. This cement stratigraphy together with internal sediment, interpreted as vadose silt, indicates late Silurian emergence and subaerial exposure. The final stages of cement growth and pore occlusion took place after reburial of the locality.