SAXONIAN MOVEMENTS IN EAST YORKSHIRE AND LINCOLNSHIRE

Abstract

Although the existence of an episode of tectonic movement towards the end of the Jurassic period has long been recognised in Europe, little attempt has been made to bring the British evidence into line with the Continental data. It has been suggested by Van der Gracht1, and later by Dr. Rastall2, that the principal belt of movement in Europe might be continued across the North Sea into East Yorkshire. Recent revision of the Upper Jurassic and Lower Cretaceous zonal ammonites by Dr. Spath3 and the useful summary of the stratigraphy of the Speeton Series from the pen of Mr. C. Thompson4 permit a more detailed discussion of the question. The European belt of Saxonian movement extends, according to Stille5, from the Crimea and the Dobrudja across Bohemia to Thuringia and Holland. While commencing at the end of Triassic times in the extreme south-east, the movement developed later towards the west, i.e. in Kimmeridgian and Portlandian times, and continued into Upper Cretaceous times. In Southern Germany the earlier movements or Cimmerian phase were of a threefold character. The discordance between Kimmeridgian and Lower Portlandian marks the beginning (Deister phase). The Lower Portlandian is separated from the Upper by a second break (Osterwald phase), and then, after continuous sedimentation during Upper Portlandian and “Wealden” times, a third phase of movement (Hils phase) took place, representing the gap between “Wealden” and Valanginian strata. Following this came a period of generally continuous sedimentation without indications of movement till the end of the Albian, when ...