366 Transactions. 



Weka Creek. — The lowest beds of the Motunau series appearing in 

 the Weka Creek are shelly conglomerates, which are followed on the right 

 bank by greenish mudstones, 20 ft. thick, crowded with Chione stutchhuryi. 

 The next beds to outcrop are a series of shell-beds yielding Ancilla novae- 

 zelandiae, Anomia huttoni, Barnea tiara Tate, Calyptraea maculata, C. tenuis, 

 Gari lineolata, Glycymeris laticostata, Mactra dubia, Mytilus canaliculus, Ostrea 

 fatei, Spisula aequilateralis, Trochus conicus, and Verconella dilatata. 

 Farther down-stream, in a high cliff near the road, there is a hard oyster- 

 bed about 6 ft. thick, from which Ostrea arenicola was identified. 



In ^ the railway-cutting 43 miles 2-3 chains from Christchurch the 

 uppermost Mount Brown limestone (E) is followed, apparently quite con- 

 formably, by a thin bed of white sand, showing on the south-west (creek) 

 side of the cutting, succeeded by about 12 ft. of shelly conglomerate. This 

 is followed by a yellow-brown polyzoan calcareous sandstone, greatly 

 resembling the underlying limestone (E), of -which 12ft. is exposed. On 

 the north-east side of the cutting, where the section is clearer, the shell- 

 bed is divided in two by a mudstone intercalation, and there are loose brown 

 sands, making a total of about 35 ft. of beds before the calcarous sandstone 

 is reached. Park (1905) interpreted the upper calcareous sandstone as 

 a portion of the Mount Brown beds, and considered that it was covered 

 unconformably by the shell-beds which really underlie it. The constituents 

 of the conglomerates are mostly coarse, hard greywackes and jaspers, but 

 basalts and rotted lamprophyre-like igneous rocks are represented. The 

 majority of the pebbles are 1 in. to 2 in. long, but a few up to Sin. were 

 observed, all well rounded. The shells collected were Amphidesma australe, 

 Ancilla novae-zelandiae, A. hebera, A. mucronata, Anomia huttoni, Cerithiella 

 n. sp., Chione chiloensis, Crepidula gregaria, Dentalium solidum, Dosinia 

 subrosea, D. greyi, Glycymeris globosa, G. laticostata, Ostrea angasi, 0. manu- 

 briata, 0." tatei, Polinices ovatus, Sigapatella novae-zelandiae, and Spisula 

 aequilateralis. 



Kowhai Series. 



The Kowhai series consists of tilted terrestrial gravels, resting uncon- 

 formably on the Greta series, and containing boulders of all the under- 

 lying Notocene beds as well as the greywackes of which they are mainly 

 composed. The beds form the lower hills adjoining the Amberley-Waipara 

 Plain, and have a larger development in the Moeraki Downs to the south- 

 west of the district, and in the hills between Amberley and the lower gorge 

 of the Waipara River. The best exposures are in the Kowhai River, 

 but the beds are also seen in the creeks draining from the Deans and in 

 the tributaries of the Omibi Creek. 



Kowhai River. — In the high cliffs of the north branch of the Kowhai 

 River north-east of Tobin's Road there are from 100 ft. to 200 ft. of 

 brownish gravels dipping at a low angle to the north-east. The gravels 

 are poorly sorted and poorly stratified, and consist mainly of greywackes, 

 grits, and jaspers from the pre-Notocene rocks, with rare basalts. The 

 boulders and pebbles vary from 1 ft. in diameter down to the smallest quartz 

 grains, and there is a good deal of clay in the cement. In general shape 

 they are angular, but the edges are always rounded. These gravels rest 

 on a clay-bed about 18 in. thick, dipping 12° south-east, which has a sharp 

 surface towards the gravels above, but passes down quite gradually to a 

 series of grey gravels. These consist mostly of pebbles of the pre-Notocene, 

 but contain also pieces of greensand, Amuri limestone, Mount Brown lime- 

 stone with Magadina browni, and red and white sandstones. 



