Rods of the Hoivqua River. 39* 



plateau is best preserved round the margin along the main Divide. 

 These relatively flat, elevated areas at 5000 feet and over are locally 

 known as snow-plain country. Iliey form summer feeding grounds 

 for cattle during a few months of the year. The Howqua valley is 

 one of the main cattle routes to these summer grazing areas from 

 the low country. A bridle track follows its course towards the 

 headwaters, where it rises to the open grassy plain near Mount 

 Howdtt. Thei economic value of the region doesi not lie in its possi- 

 bilities from a point, of view of settlement. Both from an. agricul- 

 tural and pastoral point of view^ its capabilities are almost negli- 

 gible, but it forms an important collecting ground and store-house 

 for water supply. It is here that the Goulburn gathers its waters, 

 the value of which for irrigating its fertile alluvial plains is now 

 being widely recognised. 



4. — General Geology. 



The area specially considered from a geological point of view- 

 lies on either side of' the Howqua River, with Mount BuUer in the 

 north-eastern corner^ and comprises about 60 square miles of 

 country. The diabases and associated rocks, which are specially 

 referred to in this paper, cross the tract from north-west to 

 south-east, which is the general trend or grain of the structure as a 

 whole. 



One great handicap to investigation in this region apart from 

 itsf uninhabited and mountainous character wasi the absence of any 

 map suitable for the work in hand. A surveyed traverse of the 

 Howquai River was kindly supplied by the Lands Department, and 

 with this as a basis, the re.st of the topography was sketched in by 

 means of prismatic compassi methods, which was the best that could 

 be done under the conditions. 



The rocks of this region, with the exception of a small outlier 

 of Kainozoic basalt on the summit of Mount Buller referred to by 

 Fenner^ are entirely Palaeozoic, but they range in age, probably 

 from Cambrian to LoAver Carboniferous, and include lx)th sedimen- 

 tary and igneous rocks. They may be conveniently considered 

 first in chronological order, starting with the oldest. (See Fig. 2.) 



5. — Lower Palaeozoic. 



This includes rocks which range from Cambrian to Silurian, 

 covering more than three-fourths of the area under consideration, 

 but the exact mapping of the boundaries is rendered very difficult 



