Stenenvelden in de Noordzee

The main purpose of this preliminary article is to draw attention to the occurrence of accumulations of stones, the so-called "roughs" of the fishery maps, on the bottom of the North Sea. A sketch map is given, compiled from data from fishery maps (f.i. the one published by OLSEN in 1908), navigation maps of the British Admiralty, and a sediment-petrographical map from BAAK's (1936) dissertation. From this last one only those symbols indicating a Fennos-candian origin (pure or mixed with other ingredients) of deposits on the seabottom have been copied. Several writers have given particulars of the nature of stones from the bottom of the North Sea. PRATJE (1929), and TESCH (1915) particularly, mention northern erratic boulders (porphyry, granite, amphibo-leschists) from the Dogger bank; VAN BENEDEN (1883), RENARD (1886) and DANGEARD (1928) mention cristalline rocks from the sea-bottom near the Flemish coast. At the end of this article the suggestion is made that these roughs may be remnants of the terminal moraines belonging to the icecaps of the Mindel- (from the mouth of the Thames to the isle of Schouwen) and the Rissglaciations (from a little to the South of the Wash Bay to the isle of Texel, keeping North of Lat. 53 N.).