BY T, STEPHENS, M.A , F.G.S. 10& 



found in almost every district. The ridge to tlie ISr.W. of the 

 old Storage Reservoir consists entirely of this rock. The beds 

 dip somewhat sharply to the east, the whole mass of the 

 ridge having been tilted by a movement independent of 

 those which have affected other portions of the marine beds 

 of the immediate neighbourhood. 



Next in order above the mudstone are thick bedded sand- 

 stones, which furnish most of the building stone for which 

 Southern Tasmania is famed, but this rock has been 

 entirely removed by denudation from the ridge in question, 

 though it is seen in its normal position to the S.E. of the 

 Sandy Bay Eivulet, dipping towards and partly under the 

 massive diabase which bounds the valley on that side. 

 The lowest beds of the sandstone probably represent the 

 epoch at which the floor of the tipper Palseozoic sea, 

 after being gradually built up from the waste of older 

 rocks during subsidence for a vast period of time, began 

 to emerge, and a considerable part at least of the covering 

 beds was of aerial formation. That these and other sand- 

 stones generally classed with them, as well as a long 

 series of shaly beds, and part of the southern and eastern 

 coal measures, ai'e to be seen in places distinctly conformable 

 to the Palaeozoic Marine beds, is unquestionable ; but 

 conformity does not necessarily imply continuous deposition, 

 and it is probable that a long period of time, and a distinct 

 stratigraphic break, intervened between the formation of the 

 most recent of the marine beds of the Palseozoic series and 

 that of the rocks forming the base of the so-called Mesozoic 

 coal measures. Of this, however, we have at present no 

 distinct record. 



