Beyond the almost level floor of this downfold, the chalk strata rise once more in a line of very sharp flexure, running west and east through South Dorset into the Isle of Purbeck, and through the Isle of Wight.
His concept of a great downfold or depression filling with sediment at the edge of a continent and then isostatically uplifted to produce the Appalachian fold ranges, was the first suggestion of an Appalachian geosyncline.