Thomson. — Flint-beds associated with Amuri Limestone 51 



In tte green argillaceons limestone of tlie Ure River, a little above the 

 junction of tlie Isolated Hill Creek, Teredo heaphyi occurs. Again the 

 exact horizon within the limestone cannot be stated, owing to the complex 

 faulting in the vicinity. 



In the Coleridge Creek section of the Trelissick Basin, Mr. R. Speight 

 and I recently discovered a band of fossiliferous tufi, about 25 ft. thick, 

 and interbedded 10 ft. below the top of the Amuri limestone. This tuff 

 yielded twenty-one species of Mollvsca, determined by Mr. Suter as 

 follows : — 



Calliostoma auchlandicuHi E. A. Smith. 

 Seila huttoni Suter. 

 Si'pJionum planatum Suter. 

 Polinices huttoni Ihering. 

 Polinices ovatus (Hutton). 

 AmpidUna miocoenica Suter. 

 AmpuUina suturalis (Hutton). 

 Epitonium zelehori (Dunker) var. 

 Epitonium rugulosmn lyratum (Zittel). 

 Fusintts hicarinatus Suter. 

 Hemifusus goniodes Suter. 

 SipJionalia turrita Suter. 

 Cominella intermedia Suter (?) 

 Admete trailli (Hutton). 

 Ancilla papillata (Tate). 

 Ancilla suhgradata (Tate). 

 Marginella harrisi Cossman. 

 Surcula seminuda Suter. 

 Terehra costata Hutton. 

 Limopsis catenata Suter. 

 Chione chiloensis truncata Suter. 

 Of the above, two species are new, four (or 19 per cent.) are Recent, while 

 the others are all well-known Tertiary, and mostly Oamaruian, species. 



It seems clear from these facts that the top at least of the Amuri lime- 

 stone is of Tertiary age, and that the Amuri limestone is in itself a Cretaceo- 

 tertiary rock. Cretaceous at the base and Tertiary at the top. In view of 

 this, the conformity or unconformity of the Weka Pass stone sinks to 

 a question of purely local Tertiary geology without significance for the 

 relationship of the Cretaceous and Tertiary in New Zealand. 



The Cretaceous fossils of the rocks underlying the Amuri limestone 

 have recently been studied by Mr. H. Woods, of Cambridge, and, as stated 

 by Morgan (1915), he has come to the conclusion that two distinct faunas 

 occur. " The older of these, found at Coverham, is considered to corre- 

 spond to the Lower Utatvir (approximately Upper G-reensand and Gault) 

 fauna. The younger, of approximately Senonian age, occurs at Amuri 

 Blufi and other points to the south." 



It would appear at first sight from this statement that the Amuri lime- 

 stone of the Clarence Valley (Coverham) must be separated from the under- 

 lying Cenomanian beds by an unconformity. All the natural sections at 

 Coverham and in the neighbourhood, however, show a perfectly conform- 

 able junction between the flint-beds at the base of the limestone and the 

 underlying Cenomanian mudstones. One would expect, in any case, that 

 the base of the limestone in this locality, where it is over 2,500 ft. thick 

 (including the flint-beds), would be lower in horizon than the base of the 



