132 



E. 0. Teaie : 



basic lavas and tuffs, the latter often admixed in part with fine 

 normal sediment. The nature of the deposits, while not suggesting 

 speciall}' deep-water conditions, would favour the view that they 

 accumulated over a sea floor at some distance from a shore line. 

 The cherts and tuffs are of a uniform and fine nature, possessing 

 none of the special features expected in those deposited under lit- 



MfLBDURNt' 



Up[j£r "Cambrian Sta 



Wellikciom 



3NI1VVY niV£K 



Lower Ordovician Sea 



N" 4 



Lov/tr Devonian Land Arw in& Terrestrial Volc<\noes 



N? 6. 



Loner Carbomrtrous 

 Lft(U5lrin< B<^sins 



N^ 1i. 



laqram of Successive Palaeozoic Bdsin^ 



toral conditions. The advent of OrdoYieiau time« does not appear 

 to have been marked bv any break in deposition, but the sediments, 

 still of a fine uniform nature, became more normal, for submarine 

 volcanic activity had come to an end. The distribution of land 

 and water remained much the same, and the succession on the whole, 

 therefore, is probably a conformable one, but local gaps in the 

 record appear to occur, notably in the Wellington area, where 

 Upper Cambrian is in contact with Upper Ordovician. Elsewhere 

 — as at Lancefield and Heathcote — it is impossible to determine 

 •closely where Cambrian ends and O.dovician begins. 



