375 
Details op Bores Nos. 1 to 11, jetc.— continued . 
Bore No. 11— continued. 
Depth (feet). 
Nature of Rock. 
Details and Possil Contents. 
590-595 .. 
'595-600 .. 
600 
% 
.Washed material 
Washed material 
.Fragments of black flint 
Echinodermata. — Pentagonaster sp. 
Polyzoa. — Cellepora sp. 
Pelecypoda. — Spondylus gcederopoides , 
McCoy. 
Foraminifera .—Polymorphina elegantissima, P. 
and J. ; Operculina complanata, Defr. 
Echinodermata. — Pentagonaster sp. ; Echi- 
nocyamus ( Scutellina ) patella, Tate sp. ; echi- 
noid plates, indet. 
Polyzoa. —Cellar la rigida, var. perampla, 
Waters ; Porina gracilis, M. Edw. sp. ; Celle¬ 
pora fossa, Hasw. sp. 
Brachiopoda. — Magellania insolita, Tate. 
Pelecypoda. — Spondylus gcederopoides, 
McCoy ; Pecten foulcheri, T. W. ; P. precursor, 
Chapm. 
In this bed boring was stopped. The flint con¬ 
tains numerous remains of polyzoa and forami- 
nifera, and is virtually a silicified polyzoal 
limestone. 
Notes on Bore No. 11. 
From the surface down to 148 feet the deposits are sandy and pebbly. 
Near the surface to 28 feet below, the hard, pinkish, concretionary limestone 
again appears, as in previous bores (No. 7, at 4-8 feet; No. 8, at 3-10 feet, 
represented by pale marly concretions or “ race ” ; No. 9, at 3-14 feet, and 
again at 56-69 feet and at 73-90 feet; No. 10, at 20-21 feet, and possibly 
at several levels down to 87 feet). The repeated occurrences of this con¬ 
cretionary limestone at different levels in the earlier bores points to a periodic 
accumulation of sub-aerial eroded material, with accompanying subsidence 
of the land surface, and a recurrence of the dry conditions with salt lagoons 
suitable for the production of this rock. (See note appended to Bore No. 9.) 
From 148-175 feet, Upper Pliocene and Pleistocene estuarine deposits 
are represented by green sandy clays with brackish water and shallow marine 
organisms. 
The summit of the Kalimnan series is probably touched at 175 feet, and 
may extend down to 267 feet, where the facies points to a Janjukian origin. 
From thence to the bottom of the bore the series is distinctly Janjukian 
(including the Mount Gambier, the Upper Spring Creek, and the Batesford 
facies). 
The peculiarity of the lowest 350 feet of this bore is the great development 
of the white, chalky, polyzoal rock of the Mount Gambier and Batesford 
Filter Quarries type, both in a lithological and a faunal sense. This deposit 
was undoubtedly formed in moderately deep water, as indicated by the 
numerous reteporids and the deep-water ostracod, Cythere dictyon. The 
condition of the water in which these organisms lived must have been 
remarkably clear from terrigenous (silty) sediment; for this is shown by the 
presence of certain foraminiferal and ostracodal types, as well as by the 
polyzoa, which all afford, substantial evidence as to the deepening of the 
“ Murray Gulf ” at this spot. 
