Assumptions and observations in tectonic modelling of rift basins: Some implications of thermo-isostasy, stress and rheology for intrabasinal structure

There has been a multitude of studies showing to what extent alterations in fundamental tectonic assumptions and/or modelling parameters can affect predictions on how extensional sedimentary basins evolve. However, that little is known about how mantle processes initiate lithospheric rifting/extension and affect basin evolution limits the extent to which improvements in tectonic modelling assumptions and parameter resolution can lead to a better understanding of intrabasinal or reservoir development processes. The tectonic heat budget appears to be constrained by empirical means (with the aid of kinematic models) without the necessity of a thorough understanding of the dynamic processes involved in basin formation. Nevertheless, the thermal coupling of tectonic model with intrabasinal development is sensitive to the choice of sediment thermal conductivities, An important, but often neglected, tectonic modelling 'parameter' to resolve is when the state of stress changes through time as a result of the interaction of all the known and unknown tectonic processes actively affecting the basin-lithosphere system. The occurrence of (geologically) short-lived episodes of rapid basin subsidence may be a response to a change in the tectonic setting, regardless of the relative sense of change of the ambient stress field. Recent theoretical studies suggest the same may be true for the evolution of salt diapirs. (C) 1996 Elsevier Science Ltd.