314 ME. 0. A. SHRTTBSOLE ON TRIASSIC PEBBLES OE [Aug. I903, 



apparently been derived from the same unsubmerged land at the 

 same period, rolled about, and finally laid to rest contemporaneously, 

 though possibly in disconnected inland lakes or seas. He indicated 

 the Palaeozoic ridge lying between the two areas as a probable 

 source, but observed that there was no doubt that some of the fossils 

 of the Budleigh-Salterton Conglomerate had come from Normandy 

 and Britanny. 



In 1895 Prof. Bonney 1 described the pebbles of Budleigh Salter- 

 ton, and compared them with those of the Midlands. He observed 

 the general resemblance of the two deposits, with slight differences, 

 drew attention to the occurrence of felstones and quartz-felspar 

 grits in both localities, and suggested the possibility that the ancient 

 mass of Archsean crystallines which once swept round from the 

 Scoto-Scandinavian region to North-Western France may have been 

 fringed in more than one district with rocks of Torridonian and 

 Durnessian types. 



In 1900 Prof. Bonney summed up his conclusions in a paper read 

 before this Society. 2 He regarded the Midland Bunter pebbles as 

 the work of a river or two rivers. He gave reasons for regarding 

 it as highly improbable that these pebbles can have flowed from the 

 south or south-west, or from any neighbouring district. The only 

 direction practically left was, therefore, the north, although a certain 

 portion of the material might be local. The Devon Pebble-Bed 

 might be the delta of a third river — from a more or less westerly 

 quarter, that is, from the old Armorican land, but chiefly draining 

 an area which would include a part of Cornwall and of the English 

 Channel. 



In 1902 Mr. H. H. Thomas 3 submitted to this Society the result 

 of an investigation of the fine material in the Budleigh-Salterton 

 Pebble-Bed. This led him to conclude that the flow of the current 

 which brought the pebbles with their sandy matrix was from south 

 to north ; and that there had been a tributary current from the 

 west, but north of Budleigh Salterton. 



From the foregoing general summary it will be seen that, although 

 the earlier investigations were restricted in great part to the Pebble- 

 Bed at Budleigh Salterton, and that subsequent observations had 

 reference in the main to the Midland Bunter, it has not been 

 possible to shut out considerations which involve the origin of the 

 Pebble-Beds taken as a whole. This larger enquiry may be said 

 perhaps only to have entered upon its initial stage ; and as the Devon 

 Pebble-Bed may possibly furnish us with a key to the position, I 

 propose to consider the evidence regarding that particular deposit. 



II. The Budleigh-Salterton Pebble-Bed. 

 In South Devon the Bunter Conglomerate may be observed in a 

 magnificent cliff-section, showing not only the whole thickness of 



1 Geol. Mag. 1895, p. 75. 



2 Quart. Journ. Geol. Soc. vol. Ivi, p. 287. 



3 Ibid. vol. lviii, p. 620. 



