Reconstructing the Late Cretaceous inversion of the Roer Valley Graben (southern Netherlands) using a new model that integrates burial and provenance history with fission track thermochronology

Abstract

[1] Apatite fission track thermochronology is a powerful tool for the reconstruction of the thermal and geological evolution of sedimentary basins. However, reconstructing basin evolution using thermochronological data is complicated by the fact that sediments also record the thermal history of their source areas. Moreover, samples frequently contain grains from multiple source areas. We have constructed a new numerical model that integrates sediment burial and thermal history with provenance history scenarios and that uses the derived thermal history to calculate synthetic apatite fission track data. We have applied this model to study the evolution of the Roer Valley Graben and to explore the dependency of fission track data on provenance and basin thermal history. Samples that are buried at shallow depths (<1400 m) preserve a mix of late Paleozoic and early Mesozoic provenance ages that correspond to the Caledonian and Variscan orogenic events of the sediment source areas, the London-Brabant and Ardenno-Rhenish massifs, respectively, with varying degrees of subsequent exhumation. Using this knowledge about the inherited thermal history, fission track data of Mesozoic sediments could be used to constrain the Late Cretaceous inversion of the basin with an accuracy of ±250 to ±500 m. These results show that inversion-related exhumation was localized, reaching a maximum of 750 to 1250 m in the eastern part of the basin, while not exceeding 500 m in the western half of the basin. These results are in agreement with the distribution of preserved preinversion sediments and syninversion sediment accumulations that flank the northeastern part of the basin.