27 i) Charles Fen aer : 



vial remain in places along the valley sides, at varying distance* 

 above the present bed. At Blackwood, the river cuts right across 

 the strike of the almost vertical beds, exposing anticlines and syn- 

 clines. • It is believed by Blackwood miners that the course of the 

 river is here directed by a large east-west dyke. As the river trends 

 ^outh-easterly through the ranges, with many loops and meanders^ 

 its valley is over 800 feet deep, with precipices 500 feet sheer in 

 places. From the summit of Mt. Blackwood its valley may be 

 traced through the Ranges, completely bisecting the uplifted pene- 

 plain; beyond, we may see where it opens out on to the flat country^ 

 below the Rowsley Fault scarp. 



The last few miles of the Lerderderg gorge are reproduced in 

 plan in Fig. 28, showing how the neighbouring creeks have robbed 

 the Lerderderg of its territory. One may note here the extreme 

 narrowness of the area drained by the Lerderderg; the sketch shows 

 the positions of the Korkuperrimul and Goodman's Creeks, both of 

 which, working largely in soft glacial sandstones, appear to have 

 enlarged their basins at the expense of the Lerderderg. 



Immediately the fault line is crossed, the river passes from a 

 young stage, with a valley 1000 feet in depth, to the stage of an 

 old river meandering across a flood plain, and with numerous ter- 

 races. At the northern end of the Lerderderg flats, near Kerr's 

 farm, a pretty series of terraces occurs, as reproduced in Fig. 29, 

 from a notebook sketch. The " meander belt " here is bounded by 

 two cliffs of hard glacial conglomerate C^ and Co-. Compared with 

 an ideal terrace series it will be seen that a peculiar restriction 

 occurs; while normal down-stream ''sweeping" is observable in 

 terraces 1, 2. and 3 on left bank, this has been restricted on the 

 right bank by a hard cliff of glacial material at X. This section 

 at X is also instructive insofar as it exposes evidence of a now 

 buried terrace series, cut into the old glacial beds. These terraces 

 are worthy of a more detailed study than the writer was able to 

 give. 



Just above this point, the interesting tributary of Robertson's 

 Creek enters the Lerderderg. It has a very steep grade, and has 

 built up a fan delta where it enters the larger valley. Its course 

 lies mainly along a fault junction — the eastern end of the Greendale 

 fault. It is vigorously cutting into the older basalts, glacials, etc., 

 of its right bank; the left bank is Ordovician. It appears to 

 be about to capture the head valleys of a small Korkuperrimul 

 tributary; and apparently even now receives some water from that 

 stream during heavy rains. 



