Outcrop gamma-ray logging and its applications: Examples from the German Triassic

Gamma-ray logging of outcrops is a quick and simple, yet powerful technique to better correlate well data with surface geology. It is particularly useful for integrated sequence stratigraphic analysis and for reservoir and aquifer characterisation using outcrop analogues. Three examples from the Triassic of the cratonic German Basin are discussed: (1) shallowing-upward cycles in the Upper Muschelkalk carbonate ramp with retrogradational and progradational stacking patterns; (2) evaporite-to-red bed cycles of the Gipskeuper; (3) fluvial architecture across the terminal alluvial plain system of the Stubensandstein. Such outcrop analog studies help: (1) to calibrate subsurface well log data; (2) to evaluate the heterogeneity of subsurface reservoirs (and aquifers); and (3) to provide improved data for quantitative reservoir modelling.