Cone Penetration Test characterization of middle and upper Miocene lithostratigraphic units near Antwerp International Airport

Recently published multidisciplinary studies discussed the glauconiferous sand units of the Berchem and Diest formations in large temporary outcrops near the Antwerp International Airport, east of the City of Antwerp, northern Belgium. At this location, the upper Miocene Diest Formation was subdivided into an upper Deurne Member and a lower, recently introduced, Borsbeek Member. In the current study, Cone Penetration Tests performed near the outcrops were used to geotechnically characterize the exposed units for regional correlations. For the Kiel and Antwerpen members of the middle Miocene Berchem Formation, the geotechnical expressions are nearly identical to those recently described further west in the City of Antwerp area. Contrary to the latter area, however, the upper part of the Antwerpen Member is missing, due to erosion below the Borsbeek Member. This erosion reached up to the level of a regionally occurring, compact shell bed in the middle of the Antwerpen Member, which may have protected the underlying sand from further erosion. Throughout the study area, the Borsbeek and Deurne members each show a consistent geotechnical facies, allowing for them to be distinguished on electric CPTs and thus for more reliable predictions of their areas of occurrence.