450 DR. PRELLER ON PLIOCENE CONGLOMERATES [ Aug. 1902, 
28. On PxiiocenE Guacio-FLUVIATILE CoNGLOMERATES 277 SUBALPINE 
France and Switzer~anp. By Caartes 8. Du Ricuz PRrerier, 
M.A., Ph.D., A.M.LC.E., M.IE.E., F.R.S.E., F.G.8. (Read 
May 14th, 1902.) 
ConTENTs, 
Page 
TL. Introductory 0:46.25. Sentiee epee Once oe 450 
II. Deposits in the Limmat, Aare, and Rhine Valleys ......... 450 
Tid. Deposits in the Rhone Walleyeereerre...2......2 500s 457 
TV. General Conclusions sca ee eee esac cen. eee 463 
I. Inrropvuctory. 
In a paper read before this Society in the year 1896,' I described 
a series of Glacio-Fluviatile deposits which, occurring at varying 
altitudes in the Limmat Valley above, near, and below Zurich, and 
being the indirect product of the first general advance of Alpine 
glaciers in Upper Pliocene times, appeared to show that, at the 
time of their formation, not only the great Alpine but also the 
principal Subalpine river-valleys of Switzerland had already been 
eroded approximately to their present depth, while the lake-basins 
came into existence at a later period. 
The study of a large number of other deposits in the lower parts 
of the Limmat and Aare Valleys, and along the Rhine above and 
below its junction with the Aare, and, further, of various deposits 
of so-called ‘alluvion ancienne’ in the Rhone Valley between 
Lausanne and Lyons, have, however, led me to modify my con- 
clusions with respect to the configuration of Subalpine Switzerland 
and France towards the end of Tertiary times; and the object of 
the present paper is to lay briefly before the Society the further 
evidence that I have thus collected, together with some con- 
clusions which it tends to warrant. 
II. Deposits ry THE Limmat, Aare, AND Rute Vatieys. (Figs. 1-5.) 
(1) In the paper already quoted, I showed that, as regards the 
district immediately above and below Zurich, the deposits of 
the conglomerate now generally known as ‘ Deckenschotter ’ form 
a chain along the summit-line of the range of hills on the left 
of the present Limmat Valley.” Beginning at the base of the 
1 Quart. Journ. Geol. Soe. vol. li, pp. 556 e segq. 
2 In that paper I mentioned, among others, several low-level deposits 
embedded in the Limmat Valley, which, from the partial or surface-cementation 
of the gravel to a loose Nagelfluh conglomerate, appeared to be Deckenschotter, 
but which recent comparison with more extensive and conclusive exposures 
similarly embedded in the lower parts of the Limmat, Aare, and Rhine Valleys, 
now leads me to assign to the terrace-gravels of the two younger or Pleistocene 
elaciations. This applies to the deposits near Baden and Wettingen, close to 
the river-level (op. cit. pp. 560 & 563), near Hongg and Kiissnacht (p. 565), 
and in the Au peninsula on the Lake of Zurich (p. 567). 
