Pliysiograpky of the M(cnsjield District. 



389 



of the stream is almost wholly along the margin of the granitic- 

 mass of the North Blue Range. The latter was evidently a residiial 

 previous to the deposition of the lower carboniferous mudstones, and 

 the present valley is due to the selective' erosion of the softer rock 

 along the junction. (See Fig. 6.) 



(b) Bridge Creek. — This is the other important northern tributarv 

 of the Broken River. The valley is in the level-bedded carboniferous 

 mudstones, and in its various gorges and cliffs the influence of the 

 rectangular joint planes of the mudstones is very evident. Of tlie 

 many surveyed i-aihvay routes to Tolmie, one is up this valley, but 

 owing to topographical immaturity, the engineering difficulties 

 prove a stumbling block. 



(c) Wild Dog and Back Creeks. — These lie further to the north- 

 west, and are lioth picturesque streams flowing through country of 

 granite and indurated slates. Falls 150 feet high are mapped as 

 occurring on both streams. Those on Wild Dog Creek are very 

 fine in winter, and the aneroid under good conditions registered 

 300 feet from the base to the summit of the falls. Both streams are 

 suggestive of " boat-hook bends." but whether they here bear the 

 significance attached to such bends is not evident. 



(d) Broken .ff?'rer.— Taylor, in his " Physiography of Eastern 

 Australia," says. " An interesting problem awaits the Victorian 

 student at Barjarg on the Broken River."' As will be seen from 



>< )<. X X. K 



><. K X / X 

 X X X >^ X 



A >. /< >v X 



A = present cniirse ; 



:old cour.^t 



Fig. 2, the upper Broken and Ford's Creek are parallel streams 

 for a large part of their journey, both flowing in wide valleys in 

 the soft Battery sandstones. As may be noted on any topographic 

 map of the State, the upper Broken is within the natural mountain 

 boundaries of the upper (Toulbuni. .\ line of low hills separates 



13a 



