RELICS OF THE PERMO-CARBONIFEROUS ICE AGE. 
23 
boulder, of which the portion visible above the ground 
measures 7 feet high, 18 feet long and 13 feet wide, locally 
known as the “ White Horse ” (Fig. n, Plate IX). Another 
conspicuous granite boulder embedded in a calcareous blue 
clay occurs in close proximity (Fig. 12, Plate IX). Mr. 
Campbell also noticed below the coal seams in the south 
branch of the Irwin River clays and shales containing 
granite boulders at an altitude of about 890 feet above sea 
level (Fig. 13, Plate X). On the summit of the Brockman 
Hills, at 862 feet above, sea level, Mr. Campbell detected a 
glaciated houlder of quartzite, whilst on a low rise 683 feet 
in height, about two miles to the south-east, were many 
other fine ice-scratched blocks. According to Mr. Campbell’s 
observations, all the boulders are of local origin, and : — 
“ the boulder beds probably represent terminal moraines of the 
glaciers which at that period evidently descended from the plateau 
into the sea, and the blue clays represent the subaqueous deposit of 
glacial mud or till." 
The section (Fig. 14, Plate VIII) showing the strati- 
graphical position of the boulder bed, prepared by Mr. 
Campbell, clearly indicates that this horizon is interbedded 
with marine strata and it is more than likely that the boulder 
bed itself is of marine origin, like that in the Gascoyne 
watershed. Mr. Campbell fixes the Irwin River horizon as 
being the equivalent of that of the Permo-Carboniferous 
Greta Series of New South Wales. From the fossil remains 
above this glacial horizon Mr. Etheridge inclines to the 
opinion that the Irwin River beds are rather that of the 
Carboniferous than the higher Permo-Carboniferous. 
The following is the list of fossils from these beds : — 
Nubecularia lucifuga, var. Stephens i, Howchin ; Pleuro- 
phyllum Australe , Hinde ; Productus semireticulalus, Martin ; 
Productus subquadratus, Morris ; Productus tenuistriatus, var. 
Foordi, Eth. fit. ; Productus undalus , Defiance ; Seminula 
suhtilita. Hall ; Reticularia linealu, Martin ; Chonetes Praiti, 
Dav. ; Dielasma, sp. ; FenesteUa fossula, Lonsdale ; Avicnlo- 
pecten Sprenti, Johnston ; Conocardium, sp. ; Stutchburia, 
cf. S. ( Pleurophorous ) Randsii, Eth. hi. ; Bellerophon costatus, 
J. de C. Sby., var. ; Gastrioceras Jacksoni, sp. nov. 
Although Mr. Campbell mentions erratic blocks as 
occurring on the range to the east of the area occupied by 
the Irwin River Series, he does not record the presence of 
any undoubted glaciated pavements. 
The Northward Extension of the Lyons 
Conglomerate. 
There is in the Kimberley district (lat. i6°-I7° S.) a 
large development of fossiliferous Permo-Carboniferous 
