On PVtocene Glacio-Fluviatile Conglomerates. 51 ( J 



with the incoming of an assemblage of minerals markedly different 

 from the normal southerly type, indicates an additional source of 

 supply, perhaps a westerly current. The mass of material seems to 

 have been furnished by a highly metamorphosed area, differing 

 widely in its character from any now exposed in the South-west of 

 England. The most probable source of much of the material is the 

 Armorican massif of Triassic times. 



3. 'Revision of the Phyllocarida from the Chemung and Waverly 

 Groups of Pennsylvania.' By Prof. Charles Emerson Beecher, Ph.D., 

 F.C.G.S. 



May 14th.— Prof. Charles Lapworth, LL.D., F.R.S., 

 President, in the Chair. 



The following communications were read: — 



1. * On Pliocene GHacio-Fluviatile Conglomerates in Subalpine 

 France and Switzerland.' Bv Charles S. Du Riche Preller, M.A., 

 Ph.D., A.M.I.C.E., M.I.E.E., F.G.S. 



In a paper read before the Society in 1896, the author described 

 a variety of Deckenschotter deposits above, near, and below Zurich, 

 which, occurring both on the hills and at low levels of the valleys 

 of that district, tended to the conclusion that at the time of their 

 formation, towards the end of the Pliocene Period, the principal 

 valleys and lake-basins of Subalpine Switzerland were already 

 eroded approximately to their present depth. 



Further examination has, however, led him to recognize that the 

 low-level deposits, although in manyrespects not unlike Decken- 

 schotter, are the products of the younger or Pleistocene glaciation, 

 and that only the deposits in situ on the ridge of the hills can be 

 referred to the Pliocene glaciation of the Alps. 



In the present paper, the author describes a number of further 

 deposits of typical Deckenschotter conglomerate recently examined 

 in the Aare and Rhiue valleys, near the confluence of those rivers, 

 and shows that these, in conjunction with the Deckenschotter 

 deposits of the Zurich district, indicate the almost unbroken outline 

 of a Subalpine Deckenschotter cone, which extended from the base 

 of the Alps in a north-westerly direction over a distance of about 

 25 miles, and was formed by the waters of the retreating Rhine 

 (Western) glacier and its affluents on a Molasse plateau, the upper 

 and lower ends of which were at the contours of ^00 metres and 

 500 metres respectively. 



He further describes a Feries of Deckenschotter deposits examined 

 in the Rhone Valley between Lausanne and Lyons, including the 

 extensive plateau of the Dombes, east and north of Lyons, com- 

 posed of marine marl overlain by the characteristic conglomerate 

 ferrugineux, which some French geologists still regard as pre- 

 Glacial and others as Quaternary, but which is typical Decken- 

 schotter, and in the full acceptation of the term an alluvion des 

 plateaux. The deposits thus described afford proof of the exist- 

 ence, in Upper Pliocene times, of an extensive alluvial cone about 

 100 miles in length, which reached from Lausanne (probably even 



