102 Charles Fenner : 



II. — General Description of the Area. 



The accompanying plan (Plate XIX.) shows the courses of the 

 main stream, and its most important tributaries ; the extent of the 

 basin is shown by a dotted line, and the approximate contours of 

 the area are also shown. Fig. 1 is copied from Mitchell's first map' 

 of the river and its tributaries, and shows the route of his expedi- 

 tion. 



As has been previously noted, there is u distinct preponderance- 

 of tributaries to the east, and especially to the north-east. Indeed,, 

 except for a few short valleys, there are no tributaries on the 

 western side at all. In order to more systematically consider the 

 various features, we njay conveniently divide the area into four 

 parts; these are numbered respectively. A, B, C, and D in Plate 

 XIX. 



The chief distinctions between these four divisions consist in the 

 nature of the drainage, but there are other characteristics which, 

 may be briefly summarised as follows : — 



A. — The tract between the Glenelg and the South Australian 

 border; low land, sloping gently to west and south-west. Irregu- 

 larly timbered, mostly scrubby; poorly drained, abounding in 

 swamps and lakes with low separating ridges, often of limestone; 

 some dairying and grazing, sparsely populated. Recent work shows- 

 good agricultural possibilities in this area where extensive drain- 

 age schemes are undertaken. 



B. — The tract north of the Glenelg, towards Goroke and Natimuk; 

 slightly better populated, and with a better class of land, grazing, 

 some wine and wheat; timber mostly scrubby, but abundant good 

 redgum; badly drained, abounding in lakes and swamps, and with- 

 a few wandering " creeks." 



C. — The tract enclosed by the Upper Glenelg and the Wannon; of 

 varied elevation, rising in the Dundas higlilands to 1535 feet; 

 well drained by streams flowing north, north-west, and south; well 

 peopled for the most part; good land, in places excellent, especially 

 in the open downs to the south. The underlying rocks of this 

 important area consist of a series of ancient gneisses, schists, slates, 

 cherts, with acid and basic igneous intrusives. The most elevated 

 portions (Grampians, Dundas, etc.) consist of lower carboniferous 

 sediments — purple and grey sandstones and quartzites, strongly 

 faulted; in the lower part of area C, calcareous Jurassic mudstones 

 occur; practically the whole area, up to 1000 feet, has l^een covered 

 by marine deposits of late tertiary (1 pliocene) age. 



