468 MB. E. D. OLDHAM ON THE [Aug. 1 894, 



be impossible to collect a specimen, even from one of these last- 

 named deposits, for which, taken as an individual specimen and 

 apart from its surroundings, it would not be feasible to suggest 

 some other plausible explanation of origin. 



Whether the supposition of the glacial origin of the striated frag- 

 ments be accepted or not, it will in no way affect the subaerial origin 

 of the breccias and the local origin of their constituents. If it be 

 accepted, the Abberley beds, and those of other localities too, would 

 have to be regarded as deposits analogous to the ' glacial-scliotter ' 

 of German geologists : that is to say, as a mixture of moraine and 

 scree-material, transported and deposited by streams. 



III. The Indian and Attstealian Uppee Caeeonifeeotjs 



BoULDEE-BEDS. 



I now come to the comparison of the rocks just described 

 with those boulder-beds of Upper Carboniferous age in India and 

 Australia which are regarded as glacial by observers who have studied 

 them in the field. Contrast would, indeed, be a more fitting word 

 than comparison, for I may begin by saying at once that there is 

 not the slightest real resemblance between the two. The English 

 beds consist of a mass of fragments of stone of all sizes, mixed 

 together and resting in contact with each other ; the Indian and 

 Australian beds, on the other hand, where typically developed, have 

 always a tolerably, often an extremely fine-grained matrix, itself 

 distinctly stratified, or interstratified with well-bedded rock. Through 

 this are scattered in abundance blocks of rock of all sizes, but always 

 embedded in, and well separated from each other by the matrix. 1 

 Where this is finely laminated, as is sometimes the case, the bedding 

 may be observed to bend down under and arch over an included frag- 

 meut, as is seen where a volcanic bomb is embedded in a stratified 

 tuff. 



The characters of the rock are, in fact, such as can only be 

 explained by a deposition of the fine-grained matrix in quiet water, 

 into which the large included fragments were dropped from above. 

 The abundance of these is too great to be explained by the action of 

 drift-wood ; volcanic agency is excluded by the absence of any con- 

 temporaneous volcanic beds ; and the only known agency adequate 

 to explain the facts is floating ice. That this is the true explanation 

 is confirmed by the fact that in several places the included frag- 

 ments show smoothed and striated surfaces exactly similar to those 

 produced by glaciers, and in two localities in India the underlying 

 rock shows the same smoothed, scratched, and roche-moutonnee 

 character as is produced by glaciers. 



This summary of the characters of the Indian and Australian 



1 A sketch of the Talchir boulder-bed given by C. L. Griesbach, Mem. G-eol. 

 Surv. Ind. vol. xv. (1880) pi. ii. fig. 2, shows the character of the deposit very 

 well, and may be contrasted with the photographic views in Mr. Wickham 

 King's paper (' Midland Naturalist,' 1893). The Talchir boulders are by no 

 means universally so well rounded as in Mr. Griesbach's sketch, and in the 

 marine boulder-beds of North-western India the included fragments are generally 

 angular. 



