554. T. Mellard Reade—On the Lower Trias. 
the pebbles have travelled, that they are the product of other areas, 
and this will hold good, whether they resulted from the direct 
destruction of quartzite rock, or are of secondary derivation from 
a pre-existing conglomerate. 
In framing a theory of the origin of the Bunter Sandstone, it 
appears to me that we cannot altogether detach it from a considera- 
tion of the underlying Permian. 
Before these Permian deposits were laid down, and during the time 
of accumulation, extreme denudation of the Carboniferous rocks took 
place, and much of the material was derived from them ; but on the 
incoming of the Trias, the materials became of a more uniform 
character, and were to a large extent of distant origin. It is not, 
however, improbable—nay, it is extremely likely—that the drainage 
or leaching of the Carboniferous rocks may have supplied the per- 
oxide of iron with which the grains are coated, and which gives the 
sandstones their distinctive colour. We know also, for the records 
are unmistakable, that an enormous mass of Carboniferous sand- 
stones and grits have been stripped from the Pennine Chain by 
denudation, and it is not unreasonable to ask what became of the 
resultant sand during Triassic times. The same may be said of 
the Old Red Sandstones of Herefordshire and the Quantocks. It 
would indeed seem incredible if these important formations did 
not yield their quota of sand to the Trias, though the absence of 
Carboniferous sandstone boulders in the Trias is remarkable. May - 
they not have been ground to sand by currents which we know 
were capable of rounding the hard quartzite pebbles? It appears 
to me that neither the distribution, the uniform character, nor the 
great thickness of the Bunter Sandstone, accords with the subaerial 
river-delta theory. 
No instance that I am aware of has been recorded of the finding 
in Triassic Sandstones of anything like a river-channel. It is 
difficult to conceive of a river unless fed from some very peculiarly 
constructed rocky area bringing down nothing but sand. The Nile 
does not do it; on the contrary, it covers the desert sands with fine 
mud. On the other hand, the subaerial building up of sandstones, 
proved by the boring at Bootle to be over 1200 feet thick, does not 
seem to be, considering what has been preserved of the orographic 
features of the time, a very plausible supposition. 
While considering with many other geologists that the lacustrine 
theory of the origin of the Bunter Sandstones may be dismissed as 
altogether inadequate to account for the great prevalence of current 
bedding, the presence of well-rounded quartzite and other pebbles, 
and the absence of marl except in occasional thin beds, the substituted 
riverine theory seems to me to fail for the reasons already given. 
So far I have indulged principally in destructive criticism, pro- 
verbially the easiest sort of work, but not on that account less 
necessary in an attempt to arrive at truth. J have, however, else- 
where already indicated an alternative theory,’ which I submit in 
more detail for the consideration of my brother geologists. 
1 Physiography of the Triassic Period, ‘‘ Naturalist,’ pp. 108-111, April, 1889. 
