BY W. G. WOOLNOUGH. 789 



with basalts and tuflfs. These have been described by Jaquet 

 and Deane."^ 



In a former paper by Mr. Taylor and the author,! the physio- 

 graphy of the district was described in some detail. It was 

 there pointed out that the general surface of the country is a 

 peneplain at an altitude of about 2,000 feet above sea-level, with 

 residuals of an older and higher level at about 2,300 feet. 

 The lower levels may be regarded as a series of "mature 

 valleys," rather than a peneplain by some physiographers. The 

 troughs of this lower level are, to a large extent, filled with 

 alluvial waste, varying from the coarse auriferous gravels of 

 Digger's Creek, to the fine clays of Kettle's Flat, and Woolshed 

 Flat. Such deposits as these cover quite extensive areas in the 

 north-eastern portion of Glenrock Station. Along the banks of 

 Barber's Creek, for some little distance above Glenrock Falls, 

 these allu vials have been cut into by the rejuvenated stream, so 

 that they now stand as high-level terraces about 27 feet above 

 the creek-bed. Derived, as it is chiefly, from the waste of the 

 ^conglomerate, this recent wash makes it extremely difficult to 

 trace accurately the boundaries between Permo-Carboniferous 

 rocks and the other formations of the district. 



Eruptive Rocks. 



The eruptive rocks of the district form a very interesting 

 group embracing a considerable variety of types. They belong 

 to two periods, Pre-Permo-Carboniferous plutonic and hypabyssal 

 rocks of the grano-diorite series, and Cainozoic basaltic dvkes and 

 flows. 



The first set is typified by the grano-diorite of Glenrock, the 

 granite-porphyry of Morris Trig. Station, and the quartz-por- 



* Jaquet, J. B., " The Iron-Ore Deposits of N. S.Wales." Monograph of 

 li.S.W. Geological Survey, p. 95. 



Deane, H., Rec. Geel. Survey of N. S. Wales, Vol. vii., pp. 59-65, pi. 16, 17 

 <1902). 



t Woolnough, W. G., and Taylor, T. G. ** A striking example of River- 

 Capture in the Coastal District of N. S. Wales." Proc. Linn Soc. N. S. 

 Wales, 1906, Vol. xxxi., pp. 546-554, pi. xlii.-xliii. 



