Rotliegend geology in the Southern Permian Basin: the development of synrift sediments and its relation to seismic imaging

Abstract

In order to further examine the tectonosedimentary development of the Permian Rotliegend formation in the Southern Permian Basin area, existing well log data and literature were reviewed in light of influence of basal strata on overlying tectonosedimentary development. Moreover, 2D seismic data of the Dutch Offshore was reviewed in light of syntectonic sedimentation in the Rotliegend sediments. In the North Sea area, Rotliegend sediments were found to contain six transgressive-regressive cycles and a few narrow graben structures developed during the transtensional tectonics yielding the basin. In the Lower Saxony region, straddling the contact between harder Variscan orogenic basal strata and softer foreland Paleozoic sediments, a series of large N-S oriented graben structures occur in a concentrated area. In the Mid-Polish Trough, tectonic structures from the Variscan Orogeny seem to predetermine locations of faults in the Rotliegend, however this could have several other causes. 2D seismic interpretation yielded two main phenomena: the lithological boundaries of the Rotliegend reservoir units can be mapped purely based on their seismic character, and there are two scales of lithological variations (1) the variation on the basin-scale and (2) the variation of coarse-to-fine clastics on the individual fault-block scale.