60 Prof. F. W. Sutton — On Geological Nomenclature. 



this must be my excuse for coming forward in a matter which has 

 already been so much and so well discussed. 



I do not object to the work done by the International Congress at 

 Bologna, On the contrary, I think that the names '* System," 

 "Series," and "Stage," with their chronological equivalents, can be 

 advantageously employed by British geologists in all parts of the 

 world ; and I quite agree that the term " formation " should be used 

 only with reference to the mode of origin of a rock. The term 

 "group" seems to be unnecessary, as we can always speak of the 

 Palaeozoic or the Mesozoic rocks of a country with all the accuracy 

 required when using such wide terms ; while we cannot always do 

 the same with sufficient accuracy when referring to rocks belonging 

 to the shorter periods or epochs. For example, I can speak of the 

 Mesozoic rocks of New Zealand, because the term is wide and makes 

 no pretension to accuracy. But I cannot speak of the Jurassic or of 

 the Cretaceous rocks of New Zealand with any approach to accuracy, 

 although our present unmethodical nomenclature often compels me 

 to do so; and it is on the question of correlating systems in different 

 parts of the world that I wish to lay my views before your readers. 



It is generally allowed that although deposition has been going 

 on continuously in some part or other of the earth, a complete series 

 of rocks does not exist in any one geological region : and it is also 

 allowed that the breaks in the sequence in diffei'ent regions are not 

 contemporaneous. From this it follows that the rock-systems of any 

 one geological region cannot possibly be the chronological equivalents 

 of the rock-systems of other regions. Chronological overlappings 

 must constantly occur, and consequently there is no single region iu 

 which the rock-systems can be taken as suppl^'ing a nomenclature 

 applicable to the whole world. Further, in consequence of over- 

 lapping, no table of rock-systems, collected from different parts of 

 the world, can be compiled which will show a simple sequence. It 

 is therefore quite impossible to squeeze the rock-systems of other 

 regions into those found in the European area. They will not fit. 



This being so, it is evident that, if geological nomenclature is to 

 be fairly accurate, each geological region must have a separate set 

 of systems distinguished by different names. This is allowed by 

 Dr. A. Geikie.^ But in order that these regional sj'stems may be 

 connected together, it is necessary that geological time should be 

 divided into a set of divisions quite irrespective of any particular 

 region : and the systems could then be referred to this chronological 

 scale with greater and greater accuracy as our knowledge of the 

 palseontology of each i-egion increased. 



Geological regions with separate systems would be established 

 wherever it was thought to be necessary, but in time some might 

 amalgamate, or partly amalgamate. For example, there is in New 

 Zealand a physically connected system of rocks which I have called 

 the " Hokanui system." Future investigation may prove that this 

 is the equivalent of the " Newer Carbonaceous System" of Australia, 



1 Text-Book of Geology, p. 635. 



