The Tertiary and Quaternary subbottom of the Schelde estuary near Antwerpen (Belgium)

Abstract

The subbottom stratigraphy of the Schelde estuary near Antwerpen was studied using an O.R.E. subbottom profiler. The estuary valley is incised in Tertiary and Quaternary deposits, still eroded at several places. In the Boom Clay (Oligocene) uparching and diapirs occur. They result from an unloading of the clay after one or more erosion periods. The top of the Boom Clay consists of an undulating erosion surface, dipping roughly NNE and covered unconformably by Miocene (Edegem Sands) and Pliocene (Kattendijk Sands) deposits. The contact between Miocene and Pliocene has not been observed. The lowermost Quaternary deposit consists of a gravel and shell layer irregular in thickness and unconformable with the older deposits. The recent sediment cover, where present, is less than 1m thick.