164 >^OTES ON THE GLACIAL BEDS NEAR WYNYARD. 



(c) Basalt. 



The last of the series is a cap of basalt, having a. 

 thickness of about 80 feet. Mr. Johnston is of the 

 opinion that this basalt is of very recent age (i). I am 

 unable to say anything with regard to the relations of 

 the Sandy Cove basalt and the Trachy-dolerite of Table 

 Cape. Mr. Stephens thinks that the Turritella-sandstone 

 was deposited against the Trachy-dolerite of Table Cape. 

 This would imply that the Table Cape rock is much 

 older than the Turritella-sandstone — in fact, that Table 

 Cape already formed a promontory as to-day at the time 

 when the Turritella-sandstone was deposited. I do not 

 agree with Mr. Stephens on this point, because if this 

 were so the beds ought to dip away from Table Cape, 

 but not towards it; besides, I think that the Turritella 

 sandstone is somewhat altered nearing Table Cape. I 

 think that there is not much reason to assume that the 

 Sandy Cove basalt and that of Table Cape are of such 

 widely different age as they would be if Mr. Stephens' 

 view were correct. 



The actual observations of the strata as exposed near 

 Wynyard can therefore be summarised as follows : — 



" There exists a fairly thick glacial drift unconform- 

 ably overlaid by an arenaceous littoral formation with 

 fossils capped by basalt." 



The cjuestion now arises, what is the age of these 

 deposits ? Before discussing this problem, I wish to 

 mention another observation I made, which, though of 

 the greatest importance, has apparently never been 

 • noticed by previous ob&ervers. When I examined the 

 top part of the glacial drift, with a view to ascertain the 

 relations between it and the Turritella-sandstone, I 

 noticed small lenticular layers of fossiliferous sandstone, 

 each showing the small quartz pebbles embedded in the 

 boulder clay, and later on I found rather a long layer 

 of this sand (PI. XL and XII.). There is no question 

 that these fossiliferous layers, undistinguishable from 

 the standstone above, were embedded in the moraine, 

 but the problem is to decide whether they are 

 moraine, but the problem is to decide whether they are 

 primary deposits contemporaneous with the moraine or 



(i) Geology of Tasmania, pag. 259. 



