Marshall. — Relations heUveen Cretaceous and Tertiary Rocks. 101 



Tlie following table summarizes the classifications of the younger rock- 

 series which have been proposed by varioiis geologists : — 



The rather surprising variety of opinion shown by this table is partly 

 accounted for by the isolated position of many of the coal-basins, and by 

 the somewhat confusing nature of the palaeontological collections which 

 have been made in some of the coal-bearing localities. From the purely 

 stratigraphical standpoint the perfect conformity of the members of the 

 whole series does not give room for much difference of opinion— in those 

 places, at least, where the complete series is developed. This matter has, 

 however, been dealt with at some length in a previous paper,* in which it 

 was shown that at the Waipara and at Amuri Bluff there occurs a complete 

 conformable series of sediments. The lowest beds of this sequence contain 

 distinct Cretaceous fossils, whilst the nature of the abundant fossils in the 

 highest member makes it necessary to regard this as of Upper Miocene age. 

 More recently sections have been examined in the Trelissick basin by 

 Speight which demonstrate the same fact more clearly than ever. 



In the paper just referred to emphasis was laid on the fact that the 

 series in all those three districts in which it is well developed shows in 

 its lower members a sequence of sediments that clearly indicates progressive 

 deepening of the water in which the sediments were deposited. In the 

 upper members of the series the reverse is found, for these strata show 

 that a gradual shallowing of the water was in progress. 



The order of superposition of the sediments throughout the country 

 is so similar in its general bearings that it is thought possible, and ad- 

 vantageous, and sufficiently exact, to state the succession of the strata in 

 the following order : — 



(8.) C4raveis. 



(7.) Sands. 



(6.) Mudstones. 



(5.) Greensands. 



(4.) Limestone. 



(3.) Greensands. 



(2.) Sands. 



(1.) Gravels (often with coal). 

 In those localities, such as Waipara, where the series is complete, fossils 

 which indicate a Cretaceous age are found as high in the formation as the 



* Marshall, Speight, and Cotton, " The Younger Rock-series of New Zealand. 

 Trans. N.Z. Inst., vol. 4.3, 1911, p. 378. 



