788 GENERAL GEOLOGY OF MARULAN AND TALLONG, N.S.W., 



the leaf-bearing shale-patches represent local basins or clay-pans 

 on the old sand-banks, which received their organic contents 

 mainly through wind-action. 



Hawkeshury Series. 



It is very doubtful whether rocks of the Hawkeshury Series 

 occur anywhere in the area under consideration. The Geological 

 Map of the Colony (1893 edition) shows Hawkesbury Sandstone 

 right up to the Shoalhaven Gorge, Mr. Bonney, who has made 

 a special study of the lithological features of the Hawkesbury 

 sandstone, is of opinion that the whole of the rocks of Tallong 

 differ essentially from typical occurrences of that formation. 

 The discovery of Glossopteins and Noggerathiopsis at Tallong 

 itself shows that, there at all events, the conglomerates and 

 sandstones are of Permo-Carboniferous age. 



At Moss Yale, 20 miles north of Tallong, Wianamatta Shales 

 are strongly developed; approaching Werai (3 miles from Moss 

 Vale) they are intruded and covered by basalt-dykes and flows, 

 which become very extensive between Werai and Exeter. From 

 Exeter to Bundanoon, Wainamatta Shales again become the 

 dominant surface-rocks. At Bundanoon the shales are underlain 

 by Hawkesbury Sandstone. Hence to Tallong nothing is seen 

 but sandstone and conglomerate. I understand'^' that, at Bun- 

 danoon, the base of the Hawkesbury Sandstones is sharply defined 

 by the occurrence of a thin bed of chocolate shale. This bed is 

 not visible from the train, and it is difficult, if not impossible, to 

 draw accurately the line of demarcation between the two systems. 

 Quite a distinct change in general aspect of the sandstones is 

 noticeable between Bundanoon and Wingello, and the line is 

 provisionally placed between these two Stations. 



Cainozoic Sediments. 



On the extreme east of the area dealt with in the present 

 paper, there occur small areas of Tertiary leaf-beds, associated 



* Jidt C. A. Siissmilch. 



