98 
E. DE C. Clarke, C. Teichert and J, R. H. McWhae. 
V. CORRELATION AND PALAEOGEOGRAPHY 
A complete examination of the faunas of the various fossiliferous 
dt‘posits described in this paper has not yet been made. From a study 
of the Bryozoa in the rocks of Campbell’s ‘‘opalized sea beach and in 
the limestones at the I'eninsula, Miss Crespin (see Appendix) concludes 
that they are of Middle Miocene age. Other palaeontological evidence 
is not at variance Avith this conclusion. 
At present there is no evidence as to the age of the sponge spicule 
deposits of Princess Royal, except the statement by Hinde that it is prob- 
ably younger than Cretaceous. The stratigraphic evidence presented in 
tliis paper is, of course, far from concluswe, but if the fossiliferous beds 
of CanipbeH's ‘G)i)alized sea beach’* underlie the unfossiliferous dolomite, 
if this dolomite is contemporaneous with that north of Princess Royal, 
and if the latter overlies the spongolites, then it Avould appear that the 
spongolite is Middle Miocene. 
The base of the sediments is everyAvhere about 900 feet above sea 
level. As to the conditions under which the spongolites were formed 
Hinde (1910, p. 21) stated— 
^‘It seems to me that this Norseman sponge-rock is not a merely local 
deposit, but that it Avas formed in the open ocean, at some distance from 
a coastline, so as to be aAvay from sediment-bearing currents, and probably 
at a considerable depth. The sponges Avhich furnished the materials of 
the deposit may have lived, died, and been disintegrated in the same 
area.” 
The blue clay and Avhite shale beloAV the spongolite at Princess Royal 
suggest that sedimentation began under still-water conditions. The amount 
of coarser detrital matter increases higher up in the sequence, some of the 
spongolites being quite sandy. The surface of Pre-Cambrian rocks on 
Avhich the sediments rest is uneven, suggesting a period of subaerial 
erosion before submergence. 
The fossiliferous limestones and dolomites are rather free from detrital 
material so that they may have been deposited at some little distance 
from the shoreline. On the otlier hand many of the shells are broken, 
and, in the outero]) C at the Peninsula, tbei’e is a layer which is almost 
exclusively composed of Avorn and I’ounded fragments of small Bryozoa. 
It seems likely, therefore, that these beds Avere formed in rather shalloAA^, 
disturbed water. 
The geographical position of the Norseman sedimentary area is inter- 
mediate betAveen the huge limestone platform of the NulIarl)or Plain Avhich 
begins 100 miles farther east and the smaller area, occupied by the Plan- 
tagenet Beds, which stretches Avestward along the coast from the neigh- 
bourhood of Ravensthorpe, loO miles south-west of Norseman. Both the 
Eucla limestone of the Nullarbor Plain and the Plantagenet Beds are of 
Miocene age, and it seems most likely that the Norseman sediments are 
remnants of a sheet of sediments Avhich must ha\'e once coA'ered a con- 
siderable area of tlie southern part of the "Western Australian shield. 
The Miocene transgression in "Western Australia has been discussed 
in recent papers by Clarke (193o) and Teichert (1944). These writers 
