Uttlet. — Tertiary Geology, Otiake River to Duntroon. 149 



of the limestone is easterly, at an angle of 6°. The lower part of the lime- 

 stone is very glauconitic, and contains abundant Foraminifera and small 

 echinoderms. Brachiopods also occur, being particularly abundant in one 

 narrow band about 4 ft. wide. The limestone gradually gets less glauconitic 

 and more indurated, and at the top it resembles the harder portions of the 

 Otekaike limestone. 



Pachymagas huttoni Thomson, Epitonium lyratum (Zitt.), Graphularia sp., 

 and Lima sp. were found in this upper part. 



The lower glauconitic limestone in its upper portion furnished the 

 following fossils : — 



Aetheia gauUeri (Morris) 

 Liothyrella landonensis Thomson 

 Neothyris tajnrina (Hutt.) 

 Rhdzothyris rhizoida (Hutt.) 

 Pachymagas huttoni Thomson 



Pachymagas elUpticus Thomson 

 Terebratella totaraensis (?) Thomson 

 Terebratulina suessi (Hutt.) 

 Epitonium lyratiim (Zitt.) 

 Pecten huttoni (Park) 



Foraminifera and echinoderms are plentiful in this bed. 



In the neighbourhood of Duntroon, and in other places in the Maru- 

 wenua district, prominent salients in the shape of well-rounded hills and 

 ridges are prominent above the surface of the tableland. They are capped 

 with silts or gravels, and their flanks are usually covered with soil and 

 grass, but where cuttings have been made through them fossiliferous beds 

 are exposed which correspond with the horizon above the limestone (the 

 Otiake beds). McKay clearly recognized that the form and position o 

 these salients were an index of their nature,, for, after describing them as 

 capped with gravels, which are miderlain by brown or light-coloured sands, 

 in the lower part of which lenticular masses and beds of hard sandstone 

 occur full of fossils, he says that " the fossiliferous beds underlying [the 

 gravels] will probably be found in the isolated hills behind McMaster's 

 Station " (1877, p. 57). 



The Trig. Station A is situated on one of these prominent ridges, and 

 on the road from Duntroon to the " Earthquake," which cuts through 

 this ridge about one mile and a half from the railway-line, these upper 

 fossiliferous beds crop out. In some places the fossils occurred in con- 

 cretionary masses, but usually as casts. The looser portions of the rock 

 are glauconitic and calcareous, but the fossils in these are very friable. 

 From the hardened bed were obtained Pachymagas huttoni Thomson, and 

 casts of Turritella sp., Dentalium sp., Venericardia sp. In the looser 

 deposits lying immediately above, the following forms were obtained : — 



Anomia trigonopsis Hutt. (?) 

 Cardium sp. 



Corbiila, canaliculata Hutt. 

 *Crassatellites obesus (A. Ad.) 



Cytherea chariessa Sut. 

 *Limopsis aurita (Brocchi) 

 Modiolus sp. 

 Venericardia pseutes Sut. 



These beds are the " Phorus beds " of McKay, and this appears to be 

 the locality from which he collected (Geol. Surv. loc. No. 178). These 

 beds, as pointed out above, in his earlier reports he referred to the top 

 of the Cretaceo-Tertiary, but subsequently he correlated them with the 

 Hutchii^son Quarry horizon, considering the imderlying white limestone 

 as the equivalent of the Otekaike limestone, while the basal portion of, the 

 limestone (usually very glauconitic) he referred to his Cretaceo-Tertiary 

 system. The writer is in agreement with McKay in placing the " Phorus 

 beds" in the Hutchinsonian, and believes they are the equivalent of the 

 Otiake beds at Otekaike and Otiake. 



At the " Earthquake " the limestone at the top of the cliffs is of the 

 harder whitish variety, but lower' down it gradually gets more glauconitic, 

 and in the lower 10 ft. it contains an abundance of brachiopods. 



