133 



Where one has to cross this country in a vehicle, the traver- 

 tine, outcropping in knobby and platy masses, is, for the 

 most part, developed uncomfortably close to the surface, but 

 in depressed areas it is usually covered by a thin mantle of 

 sand or sandy soil. Occasionally, superficial sand is heaped 

 up into low dunes, which aid to modify the monotonous level 

 of the country. 



Even in the areas occupied by them, it is a rare thing 

 to locate the Tertiary beds definitely by the discovery of 

 fossil remains at the surfaces, though some of the larger 

 molluscan remains have been found amongst the surface 

 travertine in specially favoured spots. Bores put down in 

 search of brown coal are gradually furnishing definite data 

 as to the distribution and details of deposition of these beds ; 

 but so far, beyond the fact that some part of the trans- 

 Murray mallee country is underlain by Tertiary formations 

 and some is not, little absolutely definite is known. 



The probability is that only in minor areas does the 

 ancient primary rock come to the surface. Elsewhere fossili- 

 ferous Tertiary beds, in greater or less thickness, either 

 horizontal or but slightly inclined, are to be expected as the 

 uppermost formation, but owing to the semi-arid climate are 

 masked at the surface by the development of a dense super- 

 ficial layer of travertine or aeolian sand formation. 



The steep cliff-like banks of the lower Murray river, 

 which latter approaches within 10 miles of Moorlands, furnish 

 good geological sections through marine Miocene (Janjukian) 

 beds which have been long explored. Patches of lower 

 Pliocene (Kalimnan) limestone are also dispersed in this region, 

 above the Janjukian, but are less regular than the latter. 



To the east of the river, in the vicinity of Tailem Bend, 

 these beds thin out very quickly, and within a few miles of 

 the river the older formation comes to the surface over 

 considerable areas. In this neighbourhood only scattered 

 shallow pockets of the Tertiary, principally Kalimnan, are 

 met with. This condition persists eastwards until Moorlands 

 station is closely approached, when a decided and continuous 

 low dip to the east carries the pre- Tertiary rocks downwards, 

 so that an ever-increasing thickening of the Tertiary beds 

 is met with as the Victorian border is approached. This state 

 of affairs is illustrated by the data from various bores quoted 

 by Mr. L. K. Ward.H) Whereas "bed roek" (pre- Tertiary) 

 is encountered at depths ranging between 50 ft. and 100 ft. 

 in most of the areas where mining activity is now proceeding 

 at Moorlands, a bore sunk at a, point 40 miles to the east 

 penetrated 852 ft. of Tertiary strata before meeting the 

 older bed rock. 



(4)Min. Rev., No. 33, pp. 72-74. 



