304 



C. A. SUSSMILCH AND T. W. E. DAVID. 



sporadically distributed through sandstones and mudstoues. 

 At about 1500 feet above the top of the Greta Coal measures 

 a well marked glacial horizon is reached, that of the 

 Bran x ton Beds in the Upper Marine Series. The glacial 

 evidences there are in the form of groups of dumped blocks 

 occasionally well striated, and up to three or four tons in 

 weight. Their parent rocks are some 150 miles to the S.W. 1 

 These dumped blocks are in the midst of Protoretepora 

 ampla and Fenestella shales, the latter often strongly 

 indented through the impact of the falling blocks, as origin- 

 ally pointed out by R. D. Oldham. 2 A typical photograph 

 is given in the work below. 3 



On a still higher horizon, at about 2400 feet above the 

 top of the Greta Coal-measures, is a remarkable calcareous 

 marine boulder-bearing conglomerate, almost a tillite. This 

 is known as the Bolwarra Conglomerate. 



With the exception perhaps of the dumped blocks 

 described by R. L. Jack in the Middle Bowen (Permo- 

 Oarboniferous) series of Queensland, and the dumped blocks 

 in the strata above the Irwin Coal Seams (Greta ? Seams) 

 in West Australia and certain erratics in the marine 

 Permo-Carboniferous rocks of Tasmania, these glacial 

 horizons of the Upper Marine Series of New South Wales 

 do not appear to be represented in Permo-Carboniferous 

 rocks in other parts of the world. The main glacial horizons 

 of late Palaeozoic age in Australia and Tasmania (other 

 than those of the Hunter District) are situated on a horizon 

 below that of the Greta Coal-measures. For example, the 

 Wynyard beds of Tasmania are below the Greta seams of 

 Preolenna, and the tillites of the Irwin River are below 

 the Greta Coal (see Plate XXIX, 4). The Bacchus Marsh 



1 This Journal, xxxin, 1899, p. 156, aud pi. 4, fig. 1. 



2 Eecords Geo!. Surv. India, xix, 41, (1886). 



3 Memoir Hunter River Coal-field, Plate xxiv. 



