546 



A STRIKING EXAMPLE OF RIVER-CAPTURE IN THE 

 COASTAL DISTRICT OF NEW SOUTH WALES. 



By W. G. Woolnough, D.Sc, F.G.S., Assistant Lecturer in 

 Mineralogy, etc., University of Sydney; and T. G. Taylor, 

 JB.Sc., B.E., Assistant Demonstrator in Geology, Univer- 

 sity of Sydney. 



(Plates xlii.-xliii.) 



Even a casual examination of a map of New South Wales 

 which shows plainly the courses of the coastal rivers will reveal 

 the fact that, throughout the greater part of the length of the 

 sea-board, the upper waters of the rivers have a marked tendency 

 to flow parallel with the coast line. This is the case particularly 

 with the Shoalhaven, Hawkesbury, Macleay, and Clarence 

 systems. The authors were independently struck with the 

 remarkable arrangement of the watercourses in the neighbour- 

 hood of Marulan and came to the conclusion, from theoretical 

 considerations, that the present structure pointed to river-capture 

 on a magnificent scale in that area. They therefore made two 

 expeditions and satisfied themselves in the field of the correctness 

 of their theoretical deductions. 



Summary of the facts. — The Shoalhaven River rises about 35° 

 57' S., 149° 40' E., about twenty miles south-west of Araluen. 

 It flows in a general north-north-east direction to near 34° 46' S., 

 150° 7' E., at Bungonia. Here it suddenly changes direction 

 and flows generally east-south-easterly and empties into the sea 

 near Nowra. The Wollondilly River rises 34° 26' S., 149° 36' E., 

 near Crook well. At first it flows south-south-easterly, but near 

 Goulburn it sweeps round and then flows north-north-east towards 

 the Hawkesbury. A tributary, Barber's Creek, enters the Shoal- 

 haven on its left bank, just at the great elbow above described, 



