Extensional models for the formation of sedimentary basins and continental margins

Two kilometers of sediment covers more than 70% of the continental crust. The major accumulations
occur in sedimentary basins and at continental shelves. The areas of maximum subsidence are often
associated with thin crust and evidence of extension. Of the concepts advanced to explain this subsidence,
uniform extension has proved the most useful. Models based on this concept account for the gross
features of the basins and shelves and provide a quantitative method for examining the history of
subsidence. However, modifications are needed to explain the detailed subsidence of most areas and to
account for regions with early uplift. Problems associated with the sum of the heave on the faults
underestimating the amount of extension appear resolved. The problem and modifications lead to
limitations in the use of the models. However, the advantage, that they require a quantitative evaluation
of all the data, more than offsets these limitations. Because of this requirement they have great value as
tools in the design of data acquisition programs.