460 PROCEEDINGS OF SECTION C. 



That ice action persisted in Permo-Carboniferous time, into the 

 age when the Upper Marine series was formed, is, perhaps, clearest in 

 New South Wales, as well as in the Bowen River Coalfield of Queensland. 

 In both those regions there are abundant erratics, in some cases showing 

 evidence of having indented the soft muds of the sea floor on which 

 they fell. Although these erratics and boulders of the Upper Marine 

 series rarely exhibit definite grooves or striae, such do occur occasionally, 

 and the great size of the blocks, which frequently weigh from 3 to 

 4 tons, makes their transport to their present positions inexplicable 

 except by the agency of floating ice. Obviously, they are far too 

 large to have been carried entangled in the roots of floating trees. 

 Clearly a vast interval of time must have separated the Lower Marine 

 glaciation from that of the Upper Marine, inasmuch as the interval of 

 time is represented by the deposition of no less than over 4,000ft. of 

 strata, including the Greta (oal measures above mentioned. 



The author would desire to draw special attention to the fact that 

 hitherto no undoubted till bed has been discovered anywhere in Aus- 

 tralasia which could be referred to Upper Marine Permo-Carboniferous 

 time. It is to be hoped that such till beds may still be found, perhaps 

 in some portion of Tasmania. Probably this Upper Marine glaciation 

 was less intense than that which ushered in the Lower Marine age. 



The next problem which suggests itself, and one of immense interest, 

 is the exact northern limit of the land ice in Permo-Carboniferous time, 

 and the height to which the ice descended in relation to sea-level. So 

 far in New South Wales, Queensland, and Western Australia there is 

 conclusive evidence of the presence of drifting icebergs in the seas of 

 Lower Marine time. Some of the most beautiful evidence is that 

 afforded by the boulder beds discovered by Mr. Gibb Maitland, Govern- 

 ment Geologist of Western Australia, in the Irwin River and the 

 Gascoyne and Wooramel R ver districts. The ice-striated boulders of 

 the latter region in particular are imbedded in what is almost a hmestone 

 largely formed of remains of the FenestellidcB. Clearly then the ice 

 must have come down to sea-level in Permo-Carboniferous time some- 

 where between the Lochinvar area in New South Wales and the Beech- 

 worth area of Victoria — that is somewhere between the parallels of 

 32° 45' and 3G° 20' S. lat. 



In South Australia undoubted Permo-Carboniferous boulder beds 

 have not hitherto, as I am informed by Mr. W. Howchin, been traced 

 further north than the Croydon bore, near Adelaide, which is in the 

 parallel of 34° 55' S. lat. 



The glacial boulders of Permo-Carboniferous age associated with 

 marine strata in Western Australia have so far not been traced further 

 south than the latitude of the Irwin River, which is 29° 10'. It is 

 much to be hoped that examinations extended still further to the south 

 may yiel 1 evidences of Permo-Carboniferous till in Western Australia. 



It is interesting to note, in connection with speculations as to the 

 direction in Permo-Carboniferous time of the prevalent winds which 

 brought the snow or moisture to supply snow to the gathering grounds 

 of these great ice fields, that in the Wynyard district of Tasmania the 



