Marshall. — Relations between Cretaceous and Tertiary Rocks. 105 



In New Zealand, pebbles of coal occur in the grit near the Selwyn 

 Eapids, in Canterbury. These beds are stratigraphically lower than the 

 marine fossiliferous beds of Cretaceous age, yet there is no doubt that their 

 coal is derived from the neighbouring coal-seams of Cretaceous age. This 

 occiirrence of detrital coal derived from beds of the same series may there- 

 fore be regarded as by no means abnormal. 



Further attention is called by Morgan to a discordance between strike 

 and dip, and to possibly unconformable contacts ; but it is stated by him 

 that such appearances may be due to faulting, which has been pronounced 

 in that district. An overlap of the Miocene over the Eocene is also referred 

 to by him as an evidence of a stratigraphical break, though this does not 

 seem to imply such a structure when it is realized that during the deposition 

 of the series of younger rocks there is throughout the country strong evidence 

 of rapid depression. No palaeontological evidence has been brought forward 

 by Morgan. Bartrum, however, says of this district, "It is a significant 

 fact that wherever both are developed the Miocene series has been found 

 to rest with perfect conformity on the Eocene."* 



Morgan has recently given a brief statement of the palaeontology of his 

 Eocene. t Among the Foraminfera is Amphistegina or a closely allied genus. 

 This appears to suggest the Miocene, or perhaps Oligocene, rather than the 

 Eocene age. Ten species of Mollusca have been identified, and nine of these 

 species are well known to occur elsewhere in New Zealand in beds that have 

 always been regarded as of Miocene age. The tenth species is undescribed. 

 Two species — i.e., 20 per cent, of this small collection- — are Recent species. 

 It is difficult to see any reason for supposing that such a fauna could be 

 characteristic of the Eocene as compared with the New Zealand Miocene. 

 Morgan has also reviewed the opinions held in regard to the stratigraphical 

 relation between the Amuri limestone and Weka Pass stone at the Weka 

 Pass.J He considers that there is some discordance, and, in opposition to 

 all other observers, suggests that this discordance may mark the plane of 

 separation between the Eocene and Miocene. He offers no palaeontological 

 evidence. 



{j.) Marshall, Speight, and Cotton. 



The position taken by Marshall, Speight, and Cotton is this : It was 

 recognized that the base of the younger series of rocks is of Cretaceous 

 age in several localities, notably at the Weka Pass, at Amuri Bluff, and at 

 Waipara ; and it was maintained that there was a clearly conformable 

 stratigraphical sequence from beds with Cretaceous fossils, through a thick 

 series of unfossiliferous strata, to beds apparently of Miocene age. Since 

 this paper was published Speight has discovered a section of a similar 

 nature in the Trelissick basin where the thickness of the unfossiliferous 

 strata is less, but the conformity of the rock-series is equally evident. 



It is a matter of common agreement among all those authors that have 

 been cj^uoted that there are many localities where the fossiliferous Miocene 

 rocks, often with coal at the base, rest directly upon the basement of the 

 older rock-series. This occurrence of Cretaceous rocks at the base in some 

 places and of Miocene rocks at others is the point which caused Hector to 

 establish the Cretaceo-tertiary series, Hutton to insist upon a Cretaceous. 

 (Waipara) and an Oligocene (Oamaru) formation, and Park to describe a 



* J. A. Bartrum, Trans. N.Z. Inst., vol. 46, 1914, p. 257. 



t P. G, Morgan, Bull. N.Z. Geol. Surv. No. 17, 1915, pp. 80, 81. 



% P. G. Morgan, Ninth Ann. Rep. Geol, Surv, N,Z., 1915, p. 92. 



