Hot fluid flow events in Atlantic margin basins: An example from the Rathlin Basin

An understanding of the thermal and tectonic evolution of sedimentary basins is essential to the effective modelling of source rock maturation and hydrocarbon charge and entrapment histories of potential hydrocarbon systems. A growing body of data suggests that a number of basins on the Atlantic margin to the west of Britain and Ireland have suffered short-lived episodes of migration of anomalously hot fluids through reservoir intervals. These events leave higher temperature signatures in affected basins than predicted from burial under conditions of vertical conductive heat transfer, and should be considered during hydrocarbon appraisal of a prospective basin. The Rathlin Basin displays a thermal history influenced by one or more such hot fluid flow events, with fluid palaeotemperatures in excess of 170°C recorded in the Permo-Triassic and Carboniferous section, and is typical of other Atlantic margin basins affected in this way.