90 THE GLACIER EPOCH OF AUSTRALASIA. 
jumbled together by the eruptive forces which more recently 
ejected the overlying basalt ? 
Surely this seems to be the more reasonable inference in 
accounting for the so-called boulder “till.” Why, in the 
pell-mell. ruin of the older sandstones, shales, and Permo- 
Carboniferous conglomerates should we omit to look for the 
broken remains of the latter conglomerates as well as 
for the broken remains of the similarly disturbed sand- 
stones and shales? And if the supposed “till” does not 
contain the fragmentary remains of the admittedly 
associated older conglomerates of Permo-Carboniferous age, in 
respect of which we have already ample evidence, as being com- 
posed of such polished and striated blocks as are found in the 
“ till,””,—What have become of them? The causes which broke 
up and huddled the older sandstones and shales must have 
also broken up and jumbled afresh the older associated con- 
glomerates; and it appears to me unreasonable, to suggest the 
intense glaciation involved in a glacial “till” theory for the 
origin of the later conglomeration, while the remains of the 
older and similar conglomerates—so intimately associated 
over a wide area with the sandstones and shales—have not. 
been satisfactorily accounted for. | 
Apart from these objections, even the most ardent advo- 
cates of the powerful dynamic agency of moving ice are now 
beginning to recognise that, while influenced by gravitation 
on steep slopes, the abrading power of ice may have a won-, 
derful grinding action; but they are far from satisfied im 
regard to its power to tear up, dislocate, and fracture the 
underlying harder rocks over which it glides, at least not to 
any great extent. The dislocations and fractures of the 
underlying rocks at Korkuperrimal, on the evidence given, do 
not appear to me to be the work of ice. 
It is not improbable also, as regards some of the examples, — 
that on abruptly sloping sides of creeks, the gravitating value 
of older conglomerates, which may have been suddenly 
thrust up by recent dislocations, may now partly overlie 
the original deposits of undisturbed older conglomerate at a 
lower level in their immediate vicinity. Such occurrences are 
common in Tasmania, where the stratified rocks of Permo- 
Carboniferous and Mesozoic are frequently faulted and dis- 
turbed by the forces which ejected the more recent diabasie 
greenstones which ramify everywhere throughout these rocks” 
in Hastern Tasmania. ‘7 
In any case, a preconception in favour of a particular 
hypothesis is apt to play the same tricks with the scientific 
Imagination as it does with the imagination of unscientific 
sentimentalists ; and in no part of a careful observer’s duty is 
it more imperative that he should guard himself by careful 
