On the Probable Source of some of the Pebbles of the Triassic Pebble-Beds of South Devon and of the Midland Counties

Abstract

The strongly-marked character of the pebbles of the Bunter and the wide dispersal of so many of them in our old river-gravels have caused a considerable amount of speculation as to their origin. The subject, however, appears to me to be not yet exhausted; and this must be my apology for adding another to the long list of papers connected therewith. I. Previous Incestigations. The first attempt to deal with the subject in a systematic way was in a paper on ‘On the Pebble-Beds of Budleigh Salterton,’ by W. Yicary & J. W. Salter, which appeared in the Journal of this Society for 1864 Iu this important paper Salter came to the conclusion that the fossils found in the Budleigh-Salterton pebbles were not British types at all, but must be referred to the May Sandstone and the Grès Armoricain of Normandy. He did not,however, deal with all the material submitted to him, and admitted the existence of ‘possibly Devonian’ forms. In 1867 the Rev. P. B. Brodie drew attention to the lithologieal and pal~eontological resemblance between certain pebbles found in the Drift of Warwickshire and others in the Budleigh-Salterton Pebble-Bed. In 1869 Thomas Davidson completed the work of J.W. Salter by showing that many of the Budleigh-Salterton pebbles did contain Devonian fossils (braehiopoda). He was inclined to look to some tract of land now occupied by the English Channel for the source of the pebbles. In the same year appeared the Geological Survey Memoir on ‘The Permian & Trias of