126 GEOLOGY MAITLAND-BRANXTON DISTRICT, 



The other section of the Lower Marine Series to be described, 

 is that obtained along the Eelah Road(Fig.3). Here, resting 

 directly on Carboniferous rocks, there is a large development of 

 mudstones and cherty shales. These attain a thickness of about 

 1,570 feet, and there has been an overlapping of more than 2,000 

 feet of strata below them. The mudstones are in the lower por- 

 tion, and have been more easily eroded than the cherts, and so 

 the former show few outcrops. The cherty shales, however, give 

 good outcrops, and, near the top, a few marine fossils have been 

 found. These include 



Crinoid stems. Eurydesma cordata. 



Spirifer tasmaniensis. Pachydomus. 



S. vespertilio. Platyschisma. 



These shales are followed by about 350 feet of massive sand- 

 stone. This contains the equivalent of the Ravensfield Sand- 

 stone, which has been quarried extensively at Comerford's Quarry. 

 This thick development of sandstones is similar to that mentioned 

 near Farley Railway Station, and, as in that case, it has been 

 included with the Farley Stage. 



Above the sandstone, there is a thick series of basalt and tuffs. 

 The basalt contains steamholes which have become filled with 

 secondary minerals, such as calcite, natrolite, etc. The tuffs 

 contain numerous fossils, amongst which are 



Fenestella(i) fossida. Aviculopecten mitchelli. 



Stenopora. A. tenuicollis. 



Spirifer tasmaniensis. Maionia carinata. 



Martiniopsis subradiata. Platyschisma oculus. 

 Eurydesma cordata. 



In the areas previously described, the development of basalt 

 and tuffs has been confined to the Lochinvar Stage, but here 

 there seems to be no doubt but that the volcanic activity took 

 place during the deposition of the rocks of the Farley Stage. 

 This area must have been close to the shoreline at this time, as 

 indicated, by the abundance, in the tuffs, of thick-shelled 

 molluscs, which inhabit shallow, turbulent waters. These tuffs 



