Joint inversion of temperature, vitrinite reflectance and fission tracks in apatite with examples from the eastern North Sea area—Discussion

Nielsen and Balling (2022) studied the thermo-tectonic history of the eastern North Sea Basin from inversion of temperature, vitrinite reflectance and apatite fission tracks in boreholes, and found no evidence of Neogene exhumation. This contrasts with previous studies that reported the removal of 500–950 m of Cenozoic sediments during Neogene exhumation, partly based on velocity-depth data in the Upper Cretaceous—Danian Chalk Group. Their result led Nielsen and Balling (2022) to ‘question the accuracy and precision of the sonic velocity method’. We submit that the use of velocity-depth data to measure exhumation is a reliable method, and that the interruption of Cenozoic burial in the eastern North Sea Basin by Neogene exhumation is a well-established geological fact. We suggest that the failure of Balling and Nielsen (2022) to detect Neogene exhumation is diagnostic of problems with their own methods, rather than reflecting on the reliability of the sonic velocity method.