Back-stripping

Back-stripping is a geophysical analysis technique used on sedimentary rock sequences - it is used to isolate factors which contribute to basin formation/filling other than sediment loading. It is a method by which successive layers of basin fill sediment are "stripped off" the total stratigraphy during analysis of that basin's history. In a typical scenario, a sedimentary basin deepens away from a marginal flexure, and the accompanying isochronous strata typically thicken basinward. By isolating the isochronous packages one-by-one, these can be "peeled off" or backstripped - and the lower bounding surface rotated upward to a datum. By successively backstripping isochrons, the basin's deepening history can be plotted in reverse, leading to clues as to its tectonic or isostatic origin. A more complete analysis uses decompaction of the remaining sequence following each stage of the back-stripping. This takes into account the amount of compaction caused by the loading of the later layers and allows a better estimation of the depositional thickness of the remaining layers and the variation of water depth with time.