54 Prof. T. G. Bonney — Physiography of the L. Trias. 



any such marine conglomerate, and, so far as I can infer from what 

 I have seen of modern mai'ine deposits, am led to belive that marine 

 conglomerates are rather limited in extent and still more in thickness, 

 under all circumstances but those which I have just mentioned. 



I proceed lastly to the facts which Mr. Mellard Reade has 

 overlooked. 



(1) No notice is taken of the resemblance presented by the 

 Bunter beds to the Alpine drifts, nagelflue, and molasse, or to parts 

 of the German Trias, deposits for which a marine origin cannot be 

 claimed. 



(2) The origin of the Bunter pebbles is treated as if it were still 

 a perfectly open question. " As regards the contained quai'tzite 

 pebbles, one set of observers contend that they came from the north, 

 another from the south, while a third considers that they have been 

 derived from the destruction of rocks in Mid-England." I venture 

 to think that this is hardly the case, unless (as appears to be the 

 habit of some geologists) we regard a hypothesis which is a mere 

 surmise as of equal value with one which is an induction from facts. 

 Mr. Mellard Beade, moreover, is not even .accurate in his statement 

 of this problem. The " quartzites," though the most abundant, are 

 by no means the only larger " materials of the sandstones." Of 

 these it will be enough on the present occasion to mention three : ' — 



(1) Granites, gneissoid rocks and schists — rare and rotten — more 

 resembling Scotch rocks than any other British, but too few and 

 ill-preserved to give any conclusive answer. 



(2) Various felstones, not rare. These as a rule cannot be 

 identified with rocks from the Midlands, Wales, the Lake District, 

 or Cornwall, but they exactly correspond with types of felstone 

 which occur abundantly in Scotland. 



(3) A peculiar quartz-felspar grit. This rock is identical with the 

 Torridon Sandstone of Scotland, and certainly does not occur above 

 ground in any part of England or Wales. 



Next as regards the quartzites. First as to those containing fossils. 

 These pebbles are very rare and different from the ordinary quartz- 

 ites. They certainly are not unlike those of Budleigh Salterton, 

 but they are -also not unlike the fossiliferous 'quartzite' of the 

 Lickey range (in the neighboui'hood of which they seem to be rather 

 more common). So that the evidence of these counts for little or 

 nothing in the teeth of that mentioned above. Next in regard to 

 the very compact hard quartzites, to which the majority of the 

 pebbles may be referred (though vein-quartz — which does not help 

 us much — is also abundant). The quartzite of these pebbles is not 

 that of the Stiper Stones, the Wre kin, the Lickey or Hartshill ; it 

 is not any quartzite known to me as occurring in England. It is 

 exactly like the quartzite of North-western Scotland, and identical 

 pebbles occur in the newer Palaeozoic conglomerates of the south- 

 west of Scotland, the sandy matrix of which is often exactly like 

 that of the Bunter. 



I make these positive statements after long and careful study of 

 1 Geol. Mag. Dec. II. Vol. X. (1883), p. 199. 



