I 



CABBONIPEROUS ROCKS OF THE SOUTHERN HEMISPHERE. 273 



to tectonic movements. At the same time the Government Geologist 

 of the Netherlands admits that the scene of this discovery is in a much- 

 faulted region, so that the evidence cannot be considered conclusive. 



(9) "While the above considerations suggest a wholly post-Pennsyl- 

 vanian and therefore Post-Carboniferous age for all our Australasian 

 strata from the base of the Bacchus Marsh beds to the topmost of our 

 Giossopteris flora beds, the survival in the West-Australian Permo- 

 Carboniferous beds of Productus semireticulatus, Cleiothyris maclea- 

 yana, Ac, and the occurrence at Seaham in New South Wales of 

 Aneimites in the basal portion of the Lochinvar Glacial series suggests 

 an age as old at least as Upper Carboniferous, but in this regard the 

 words of Diener are worth quoting.^ 



On p. 144, Diener says : ' Bearing in mind the gradual passage 

 from an Upper Carboniferous to a Permian fauna through the inter- 

 mediate group of rocks, the question to be answered is which con- 

 sideration is of the greater importance in defining the boundary 

 between the two systems, the appearance of a new group of cephalopods 

 which become of an unparalleled stratigraphical value in Mesozoic 

 times, or the presence of a belated fauna composed of forms which 

 are generally not well adapted for the characterisation of narrowly 

 limited horizons? ' 



In my opinion, all the strata from the base of the Bacchus Marsh 

 beds to the top of the Newcastle series of New South Wales will yet 

 prove to be post-Pennsylvanian, and therefore post-Carboniferous in 

 the European use of the term Carboniferous, and yet the lower part of 

 the Southern Hemisphere Permo-Carboniferous strata may be infra- 

 Eothliegendes. 



Nevertheless, the term Permo-Carboniferous had better be retained 

 for the present. 



Question 7. Discordance of junction between Carboniferous and 

 Permo-Carboniferous in Southern Hemisphere. 



(A) Discordance. 



(1) At Ashford, near Inverell, in New South Wales, there is an 

 immense unconformity (almost a right angle between the directions of 

 bedding) between the Gangamopteris (Greta) Coal Measures and the 

 Productus semireticulatus limestone series. 



(2) At Pokolbin, near Cessnock, in the Maitland district of New 

 South Wales, there is a marked unconformity with strong overlap 

 of the Lower Marine series on to the Aneimites series. 



(3) In the Nandewar Eanges, New South Wales, there is a strong 

 unconformity between the Giossopteris Coal Measures of Newcastle (?) 

 age and the Carboniferous strata. 



* Amer. J own. of Sci. vol. xxii. Aug. 1906, 'The Russian Carboniferous and 

 Permian compared with those of India and America : a Review and Discussion,' by 

 Charles Schuchert. 



1915. T 



