Fig. 6

Conceptual envelope of apatite fission track (AFT) age distribution in a vertical sediment column from the apatite partial annealing zone (APAZ), after uplift at time t, and geometric assessment of the missing overburden of exhumed and eroded topmost sediment column. The three diagrams show a a conceptual model of increasing detrital AFT ages for the youngest age cluster with increasing sedimentation age but no annealing, b a conceptual model taking into account age decrease by partial annealing within the APAZ, and c a conceptual method of determining the thickness of eroded sediment after exhumation during time t (for explanation, see text). Note that the spectrum of measured detrital ages in Alpine sediments of the foreland basin in fact varies stronger with time than mirrored by the youngest age cluster shown here