Fluids in sedimentary basins: an introduction

Abstract

Understanding paleohydrologic systems in terms of basin evolution requires the integration of information derived from the sedimentology, stratigraphy, diagenesis and geology of basin-filling successions. Combination of these is prerequisite for realistic basin analysis and to guide any hydrologic or geochemical modeling. Ancient basins, in particular, represent systems that can record protracted burial histories, thereby constraining the composition of specific fluid events that normally affected vast areas. The papers in this volume are concerned with tracing the fluid history of several sedimentary basins. These papers, which were presented in a special session at the Geological Association of Canada and Mineralogical Association of Canada meeting in Calgary, Alberta, Canada in May 2000, illustrate some of the methods, techniques and approaches required to document significant fluid events in basins and how this information can be used in some cases to evaluate the economic potential of basins. The focus of these studies deals with the interaction between basinal fluids and both chemical and clastic sediments. Both types of sediments can act as principal aquifers or aquitards for fluids in basins because of their changing reactivity and permeability as basins evolve.