204 



Influence of the Physical Character 



yet, if conducted with ordinary care, and with impartiality, 

 it cannot fail to place in a new and important point of view, 

 many questions of great public interest ; of greater interest 

 here, than in other climates where the hydrographical fea- 

 tures are of a different character ; and whatever errors may 

 occur, they will be out of all proportion to the useful results 

 of such an inquiry. 



Geological Formations of Victoria, — This country may 

 be described as consisting of vast beds of sandstones, shale, 

 and clay slate, members of the Primary Fossiliferous series. 

 These beds are variously contorted, and dipping at angles 

 of 30°, 40°, 60°, and 70°, and they are sometimes ver- 

 tical. Mr. Selwyn,* the Government Geologist, estimates 

 the thickness of these deposits at 30,000 feet or more, and 

 this is probably very near the truth. These sandstones and 

 clay slates have been upheaved by Plutonic rocks, which are 

 found to occupy comparatively large areas. The hills in 

 the Ovens district. Mount Alexander, Mount William, and 

 the hills in the north-eastern parts of the province, are 

 granitic, and excellently illustrate the character of such rocks. 

 Then, there are plains of basalt, sometimes of great extent, 

 where the subordinate rocks are entirely hidden, or only 

 appear in isolated hills of some height, or where denuding 

 causes have removed the upper basaltic formation. 



Basalt is alsQ found filling the valleys, near the rivers, ^nd 

 in such cases the streams have cut a passage between the 

 former rock and the clay slate ; as may be seen in some parts 

 of the river Yarra, in the rivers Coliban and Campaspie, at 

 the Deep Creek near Mount Greenock, and in many of the 

 streams in the western part of the Province. 



A considerable part of the Great Dividing Range is com- 

 posed of igneous rocks, and they in like manner form isolated 

 hills in many localities, which sometimes attain a considerable 

 altitude — as Larne Baramul, Mount Boninyong, Mount 



* " The great longitudinal extent of the auriferous deposits is a fact, not 

 difficult of explanation, when we regard what appears to be the general geolo- 

 gical structure of the country, which, in making a section from east to west, or 

 from the Australian Alps to the Pyrenees and Grampians, is found to consist of 

 a succession of steep hills, ranges, and gulleys, composed of an enormous thick- 

 ness (30,000 feet, or more) of upheaved and contorted palaeozoic and older strata, 

 intercepted by great masses of granitic and other apparently non-auriferous 

 plutonic rocks^ with extensive intervening tracts of recent igneous or volcanic 

 rocks, forming plains and table lands, also non-auriferous, but, in all probability, 

 often resting on and concealing auriferous deposits." — See jpage 10, Oeological 

 Surveyor's Ee;ports 1854. 



