Thomson. — Geology of Middle Waipara and Weka Pass District. 385 



iieighbourliood of Greenhills, Gore Bay, the Jed River, and the upper 

 Motunau, and a single bone has been obtained from the Malvern Hills in 

 the concretionary beds above the Selwyn Rapids beds. 



All the aboye beds which are correlatives of the Piripauan of the Waipara 

 occur in the area between the Rakaia River and Kaikoura Peninsula, and 

 in all these localities, except in the Malvern Hills, the Amuri limestone is 

 found above the Piripauan. The only other beds of the same age in the 

 South Island are those of Shag Point, doubtfully referred here. The fossils 

 are poorly preserved, but they appear to include a Trigonia allied to 

 T. pseudocundata, Hector and Pugnellus marslialli Trechmann. 



In the North Island, Piripauan beds may occur in the east coast of 

 Wellington Province and in the Gisborne district, but further exploration is 

 wanted in these regions. In the North Auckland district there is a limestone 

 somewhat similar to the Amuri limestone — viz., the hydraulic limestone — 

 and it is imderlain in the Kaipara district by mudstones, greensands, 

 and brown sandstones, yielding ammonites and other molluscs, and a 

 saurian bone. Marshall (1917b) described two species of ammonites as 

 Kossmaticeras with Senonian affinities, a third as Lytoceras sp. with Utatur 

 affinities, an Oamaruian mollusc {Panope worthingtoni Hutt.) identified by 

 Suter, and a cast of Phacoides (Here) sp., a genus which did not live before 

 the Eocene according to Cossman ; and, moreover, he considered that the 

 beds containing this fauna rest upon a Miocene limestone. Comment seems 

 almost unnecessary. Woods has made it clear that the Clarentian and Piri- 

 pauan faunas of Marlborough and Canterbury are typical Cretaceous faunas 

 without any intermixture of Tertiary species. The probabilities seem to 

 be that Piripauan beds are present in the Kaipara district, and that the 

 Oamaruian Gibraltar limestone is faulted down, and does not really underlie 

 the Piripauan. Panope worthingtoni Hutton is one of the species of which 

 the type was missing when Suter redefined the Tertiary Mollusca, but 

 Marshall's figure agrees very closely with Woods's figure of Panojoe clausa 

 Wilckens from Amuri Blufi. The affinities of the specimens classed as 

 Lytoceras sp. and Phacoides {Here) sp. may be neglected until better speci- 

 mens are available, since neither retained the external ornament. 



The hydraulic limestone also occurs in the Whangarei district, and 

 Piripauan beds are also to be expected here, but no distinctive fossils have 

 yet been found. 



KAITANGATAN-AMURI LIMESTONE. , 



The reasons for which I have correlated the Amuri limestone with the 

 Kaitangatan are that the Wangaloa beds of the Kaitangatan contain a fauna 

 intermediate between those of the Piripauan and the Oamaruian, while the 

 Amuri limestone occupies a stratigTaphical position between Piripauan and 

 Oamaruian. No common species have yet been described. Trechmann 

 (1917) considers, on the evidence of the Mollusca, that the Wangaloa beds 

 "should apparently be of Maestrichtian age." Chapman, on the evidence 

 of the fish-remains and Foraminifera, considers the Amuri limestone of 

 Danian age. 



In 1916^ I stated my conviction that the Amuri limestone is in itself a 

 Cretaceo-Tertiary rock, Cretaceous at the base and Tertiary at the top, the 

 reason for the latter statement being the occurrence in the Amuri limestone 

 of the Trelissick Basin of an Oamaruian fauna in a tuS band 10 ft. from 

 the top of the limestone. The rock I termed the Amuri limestone in the 

 Trelissick Basin has the same stratigraphical position — i.e., it lies above 

 rocks with a Senonian fauna, and underlies rocks with an Oamaruian fauna — 



13— Trans. 



