158 EEV. A. lEVIXa ON THE EED-EOCK 



Mglier and older Alps) undergoing subaerial waste, and not of 

 necessity resulting altogether from subsequent upheaval. Por the 

 most part the (false) dip is probably only current-bedding on a large 

 scale. Vast accumulations of such detrital matter are not unfre- 

 quently met with- in the wider parts of modern Alpine valleys as the 

 work of great downpours in the mountains *. 



(3) These breccias, as compared with the softer rocks of the Trias 

 (even though the matrix is much less calcareous), are much more 

 indurated. This may not appear so manifestly on the weathered 

 surface of the rocks as where the rock is quarried and used for 

 building-stone. 



(4) As pointed out long ago by Mr. Godwin- Austen t, and more 

 recently by lEr. Ussher J, the materials of the breccia-series appear 

 to have been derived wholly from the adjacent primaeval land, 

 exactly as those of the Eothliegendes are traceable to the older 

 porphjTitic and other rocks of Thiiringen, where they flank that 

 ancient mountain-island, and to the syenitic rocks of the Dresden 

 region further to the east §. On the other hand, the materials of 

 the Triassic series (as that term is limited in the present paper) do 

 not admit of such a distinct derivation ; they are rather admixtures 

 of reconstructed materials from the breccia-series with materials 

 brought from other and probably more distant sources. The dis- 

 tinction holds good in the Devonian region as in that of the 

 Thiiringerwald and other parts of Central Grermany. 



(5) The larger fragments (boulders, in fact) included in these 

 breccias seemed, so far as I observed them, to be just about as much 

 rounded off by the rolling action of water as we commonly observe 

 in the diluvial detritus which is frequently met with where great 

 mountain-gorges terminate in lakes. The valleys, moreover, which 

 intersect the JSTorthern Alps often exhibit just such accumulations of 

 detritus for miles, in the clean sections cut by the erosive action 

 of the present (and, in some cases, of older) rivers. 



On the other hand, I failed to observe a single " pebble " of the 

 Salterton type in any of the sections of these breccias or in the 

 blocks of fallen debris on the shore, though constantly on the look- 

 out for them ; and inquiries made of intelligent residents at Teign- 

 mouth led to the same negative result ||. 



* A few summers ago I observed such a widespread sloping mass of material 

 brought down from the mountains bj- a single storm, and spreading (with a 

 general slope of about 10°) right across the wide ralley below Davos-am-Platz ; 

 fields and gardens were all obliterated, and the high, road had to be re- 

 excavated, a good example of a Schlar/wistrom. Similar work was done in the 

 Puster Thai in the autumn of 1885. Cf. also Lyeh, ' Student's Elements,' 3rd 

 ed. pp. 19, 20, and fig. 7. 



t Trans. Greol. Soc. vol. vi. pp. 453-7. 



+ Loc. cit. p. 388. 



§ See Quart. Journ. Geol. Soc. August 18S4. Compare also the derivation 

 of the " Brockram " of the Yale of Eden from the Carboniferous Limestone 

 (Geikie, ' Textbook,' p. 758). 



II I made a special, though fruitless, search for them in tbe enormous quan- 

 tities of fallen material of the more conglomeratic strata between the Ness and 

 the inn known as Labrador. 



