Middle Tertiary {Miocene'). 
87 
The rocks consist of whitish and yellowish -brown sandy calca- 
reous layers, sandy ferruginous layers, yellowish sandy limestones, 
coralline limestones ; composed almost entirely of fragmentary 
shells and polyzoa, and calcareous clays. Near the mouth of the 
Gellibrand is a bed of conglomerate resting upon and composed of 
roiled fragments of the Oligoceno clays which occur there. There 
are also some black clay beds, containing leaf impressions, east of 
the Gellibrand, near where the Miocene beds thin out on the 
Mesozoic rocks. Similar clays occur westward of the Aire River, 
near Capo Otway, and at Point Addis. The cliffs on the coast 
near Spring Creek, south from Geelong, have been described in a 
report and geological map of that district by the late Sir R, 
Dai n tree. The thickness exposed is about 300 feet, of which the 
upper portion, of about 100 feet, consists chiefly of yellow sandy 
limestone, composed principally of polyzoa and fragments of 
echini spines. The principal characteristic fossils of these upper 
beds are Cellepora Gambierensis , Spatangus Forbesi, and Tercbra- 
tula Compta . Next in descending order come about 150 feet of 
yellow and brown sandy clays, containing a prevalence of bivalve 
shells, principally Pectunculus laticostatus and pectens. Below 
these are Oligocene beds, containing principally univalve shells. 
Some of the limestones are very hard and compact, and blocks 
may be obtained near Geelong and at Maude, on the Moorabool, 
showing, when polished, handsome shell markings. 
Near Melbourne, the Miocene beds, passing under the Older 
Volcanic rocks, consist of white clays, containing leaf impressions. 
(Fig. 33.) (Fig. 33.) 
The marine Miocene beds 
extend inland beneath the 
a Very ferruginous, coarse-gritty sandstones, fine reddish-yellow sandstones, and con- 
glomerates with numerous marine fossils, and beds with impressions of leaves of 
lauraoeouH plants. West of the Saltwater River these beds arc overlaid by Newer 
Volcanic rock. 
b Older Volcanic rock, much decomposed, concentric structure, a core of hard, dense 
basalt, surrounded by layers of variously coloured olavs with ferruginous opal decom- 
posed aragonite, &c., the shrinkage cracks filled in with brown iron-ore. 
c White clays with faint impressions of leaves. 
d. Upper Silurian (bed-rock). 
Upper Tertiaries for many miles; they are exposed along the Gle- 
iieh r , the Hopkins, Cardie’s River near Cobden, in various 
localities north of the Cape Otway Ranges, and for long distances 
up the Moorabool and Leigh Rivers. 
There is no doubt that they underlie the greater portion of the 
western plains. At Mount Mary, an extinct Newer Volcanic crater, 
near the Wcrribee, ejected blocks of rock containing Miocene 
fossils occur among the volcanic ash and other materials of which 
the hill is composed, showing that the Miocene beds underlie the 
