The Older Tertiaries of Maude, etc. 181 



The eocene rocks occupy an area of slightly elevated ground 

 flanking the ordovician i-ocks which extend south from Steiglitz. 

 To the east, south, and west, the country is covered by an 

 almost unbroken sheet of what is generally called the " Newer 

 Volcanic Rock." The surface of the exposed eocene rises slightly 

 above the level of the basaltic plain, and the geological boundary 

 is marked on the west by the valley of the Moorabool River, 

 and on the east by that of Sutherland's Creek, the two streams 

 meeting a little to the south of the area. The eocene beds 

 uaderlie the basaltic plains and are exposed wherever the streams 

 have cut through the overlying rock, which extends from Port 

 Phillip to beyond Hamilton in the west. The valleys of the two 

 streams above alluded to are very striking features in the 

 district. Aneroid measurements showed their depth to be about 

 250 feet in each case, and the Moorabool Valley averages about 

 a mile in width, while that of Sutherland's Creek is slightly 

 narrower. It is in the sections displayed along these steep sided 

 valleys that the geology of the district can best be studied. 



The bed rock of the immediate neighbourhood is ordovician, 

 l)ut granite outcrops frequently between the Anakie Hills and 

 the Dog Rocks, near Geelong, both of which are composed of this 

 rock. Aided by the quarter-sheet, we examined all the marine 

 eocene outcrops we could tind, and a description of the more 

 instructive sections will make the structure of the district clearer. 

 On the Moorabool, a section line is indicated on the map 

 crossing the valley, and passing through an outcrop of limestone 

 underlying the older volcanic rock. This line we examined 

 carefully. The surface soil on the east of the valley is very sandy, 

 so that there is at first a very gradual descent towards the 

 stream. The section is approximately as follows : — 

 Eocene — 



Sandstone passing down into limestone ? 40 feet. 

 Limestone ... ... ... 10 ,, 



Older volcanic ... ... ... 120 ,, 



Sandy limestone and conglomerate ... 30 ,, 



Ordovician — 



Slates and sandstones ... ... 40 ,, 



240 feet. 



