12.—REPORT ON THE BRYOZOAN LIMESTONE AT 
FLINDERS. 
(By A. E. Kitson , F. G.S.) 
The exposure of bryozoan limestone at Flinders occurs in a low cliff on 
the ocean beach, near the point where the extension of the main road from 
Bittern railway station to Flinders strikes the coast. The cliff section 
shows basalt at the base, overlain in ascending order by an irregular thin 
bed of conglomerate, bryozoan limestone, volcanic clay, and, some distance 
back from the shore, by white blown sand. The accompanying sketch 
section illustrates roughly the deposit:— 
SKETCH SECTION OF BRYOZOAN LIMESTONE AT FLINDERS. 
SCA L£. Hor. 80 FT , Vert. 40 FT fo anlnch. 
The basalt stretches out to sea, and the beach at this point at low water 
is composed of basalt, which for the most part forms a ragged pavement, 
while in sharp-edged patches here and there the rock stands up from 2 to 3 
feet above the general level. It is a fine-grained, hard, dense, dark bluish- 
grey rock. 
In this basalt pavement there are numerous small and large pools left by 
the receding tide. These range from a foot to several feet in diameter, and 
have apparently been caused by pot-hole erosion. 
Between this low-water beach and the limestone section is a strip of 
white sand about 20 vards wide. 
The basalt immediately under the limestone is greatly decomposed, being 
almost turned into grey and yellowish-brown clays. It is much jointed in 
more or less horizontal layers, and in these carbonates of lime and magnesia 
have been deposited by infiltration. 
In the eastern portion of the section exposed, a thin bed of conglomerate 
consisting of basalt pebbles separates the basalt from the overlying limestone, 
but in the western the limestone rests directly upon the decomposing basalt. 
The conglomerate band varies in thickness from 3 inches to 1ft. 6in., 
and the pebbles of basalt are cemented together by ferruginous clays con¬ 
taining odd grains of water-worn quartz. 
The limestone is composed of bryozoa, echinoid spines and tests, 
calcareous sponges, and foraminifera (such as Nummulites variolaria ), with 
fragments, mostly small, of lamellibranchs (such as pectens), brachiopods ? 
4541. D 
H.W.M. 
