THE SOUTHERN COAL FIELD TABLELAND BASALTS. 245 



The evidence in support of the foregoing is as follows: — 



1. Palceontological. 



In the Wingello District, beds underlying the areas of 

 basalt contain fossil plant impressions which have been 

 identified and described by Mr. H. Deane. The forms are 

 considered by Mr. W. S. Dun to belong to a late Tertiary 

 or possibly Post Tertiary period, so that palseontological 

 evidence points to the sedimentary rocks immediately 

 underlying the basalt representing, at the very oldest, a 

 period of late Tertiary deposition. 



2. Age of the uplift. 



These late Tertiary deposits are found at an average 

 altitude of over 2,000 feet above sea level, but their com- 

 paratively low altitude at the time of deposition is indicated 

 by the absence of any evidence as to contemporaneous 

 precipitous river valleys, and the fine grained nature of 

 most of the sediment. Hence we may assume that the 

 uplift took place during transition to the Post Tertiary 

 period. 



3. Faulting follows uplift. 



The uplift is confined to the central portion of the area 

 under review, and north from a line projected through 

 Kiama and Robertson, the land surface not only sagged 

 behind, but also merged into an area of subsidence. Similar 

 conditions pertain at the southern end of the uplifted area, 

 and the movement gradually dies away south from Termeil. 



The faulting found in the Southern Goal Field is confined 

 to the areas which sagged behind during the uplift, and 

 consequently underwent severe straining and fracturing. 



It is in these areas that evidence of volcanic activity 

 is most pronounced. 



4. Faulting preceded volcanic intrusions. 



There is abundant evidence that the faulting preceded 

 the volcanic intrusion, but only two instances need be cited. 



