Quantification of tertiary exhumation in the UK Southern North Sea using sonic velocity data

Sonic velocities from the Upper and Middle Chalk (Upper Cretaceous), the Bunter Sandstone, and the Bunter Shale (both Lower Triassic) were used to independently quantify apparent exhumation in the UK southern North Sea. Apparent exhumation is the displacement, on the depth axis, of a given velocity/depth trend from the normal (unaffected by exhumation) trend. The amount of exhumation of the rock column is greatest on the recognized inversion axes, where it reaches approximately 2.5 km. However, there was a regional component of 1.0-1.5 km exhumation during the Tertiary that affected structurally uninverted areas, and on which the more localized inversion-related exhumation was superimposed. -from Autho