Geological and mineralogical investigation of Rotliegend gas reservoirs in the Netherlands and their potential for CO2 storage Underground storage of CO2 is receiving growing attention by the industry as an option to reduce CO2 emissions. Rotliegend sediments of Permian age exhibit under certain conditions good reservoir quality and therefore may offer a suitable candidate for underground storage. The current study aims at analysing Rotliegend reservoir rocks in terms of mineralogical features diagenetic mineral types the determination of the availability of minerals within the rock and mineral (reactive) surface areas which are exposed to open pores and the integration of these results in CO2 water rock simulations. Target areas are Rotliegend sandstones from the northeast Netherlands which were deposited within the North German Basin and were buried to about 2000 3000 m depth. These sandstones are heterogeneously built up by different detrital and authigenic minerals. Amongst other things the size distribution and accessibility of these minerals within a sandstone body regulate the availability of chemical species for CO2 water rock interactions in the pore space and was analysed by petrographic investigations and image analysis on thin sections. ...