Carbonate diagenesis and sedimentology in an icehouse world

• Main Author: Paterson, Richard James
• Published: University of Bristol 2007
• Subjects: 551.609012
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492466

Early diagenesis of icehouse carbonate is complex, but can significantly modify depositional porosity and permeability. During icehouse times, high-amplitude highfrequency sea-level oscillations cause subaerial exposure, with vertical migration of meteoric hydrological-zones (vadose, fireshwater and mixing-zone) through the platform sediments. Repeated cycles of subaerial exposure and associated meteoric diagnesis result in significant porosity inversion, as carbonate grains are dissolved and re-precipitated as calcite cement. This diagenetic overprinting generates a complex pattern of cementation and secondary porosity and permeability, the distribution of which cannot be predicted simple through study of diagenetic products.