Meteoric-water incursion into marine turbditic sandstones: Evidence from the Andrew Formation (Paleocene), UK Central Graben, North sea

摘要

Petrographic and stable carbon and oxygen isotope study revealed extensive meteoric water incursion during diagenesis of deep-water marine Paleocene turbidite sandstones in the North Sea (Andrew Formation, UK Central Graben). Meteoric-water diagenesis resulted in the dissolution and kaolinitization of framework silicates and cementation by calcite and methanogenic siderite and Fe-dolomite/ankerite. Incursion is envisaged to have occurred over large distances along well-connected, permeable shelf, slope and turbidite sand bodies during major fall in sea level, which resulted in exposure of the continental shelf. This work urges for consideration of the impact of undersaturated meteoric waters on reservoir-quality modifications during hydrocarbon exploration in marine turbidite sandstones.