Speight and Wild. — Weka Pass Stone and Amuri Limestone. 85 



The underlying beds are of Amuri limestone as typically developed, 

 very white, with flaky jointing and nodules and masses of flint, and with 

 borings filled with greensand. Over this lies, with the intervening beds 

 obscured by gravel, a glauconitic limestone, with inclusions of Amuri lime- 

 stone which is decidedly phosphatic, the thickness being uncertain but 

 certainly not more than 3 ft., the upper portion containing more of these 

 than the lower part. It is succeeded without any unconformity by a much 

 more glauconitic limestone — in fact, a greensand — from 6 in. to 8 in. thick, 

 containing borings, and also small, dark, oxidized nodules. This is followed 

 by a glauconitic limestone, also with nodules, which become smaller and 

 smaller in the higher levels. The glauconitic character is very marked, 

 with a concentration of the glauconitic material in well-defined layers ; 

 and borings filled with more highly glauconitic material occur throughout 

 the whole thickness of the bed. This is succeeded in about 30 ft. (?) by the 

 ordinary type of Amuri limestone, which very occasional glauconitic layers. 

 No flint was observed in the upper part of the limestone. The whole section 

 is strongly reminiscent of that at Weka Pass. 



Puhipuhi Valley and Long Creek. 



The limestone up the Puhipuhi Valley and that occurring up Long- 

 Creek on the southern side of the Hapuku River were also examined in 

 order to see if any similar horizon occurs marked with phosphatic nodules, 

 but with unsatisfactory results. The best exposure that was encountered 

 was in a cutting just past the bridge over the Clinton River, a similar 

 junction, somewhat obscured, being observed in the gorge of the Clinton 

 River itself. The beds in this locality are much folded, and have suffered 

 crushing as a result of folding and faulting movements, so that their strati- 

 graphy is not clear. In the road-cutting to the north of the bridge the 

 beds strike east-north-east, and dip north-north-west at an angle of 60°. 

 The ordinary Amuri limestone is succeeded by layers of calcareous greensand, 

 the layers being more or less glauconitic through about 15 ft., some being 

 distinctly greensand. This is succeeded by hard greyish-green arenaceous 

 limestone, well jointed, and with bands of more greenish tint running 

 through it. It is much crumpled and faulted, and at least 70 ft. thick, 

 and passes up into layers of more arenaceous character. This limestone 

 is decidedly phosphatic. There is a strong similarity to the beds exposed 

 some ten miles away at Lyell Creek, but no nodules of phosphatic nature 

 were met with. Although they are apparently absent, it seems quite 

 reasonable to maintain that the junction is on the same horizon. There 

 is no evidence of unconformity. 



Contact op the Grey Marl with the Underlying Limestone. 



Although discussion of this contact is not directly connected with the 

 principal subject of this paper, it has some bearing on the question, and 

 therefore a description of all the contacts noted is here included. As the 

 grey marl is easily eroded and apt to weather readily into soil, good ex- 

 posures are rare. Those examined, however, show certain features which 

 resemble the contact of the Amuri limestone and the Weka Pass stone, 

 notably the bored upper surface of the limestone and the presence of 

 detached fragments of the lower layer included in the higher, and it seems 

 reasonable that if unconformity is demanded in one case it must also be 

 demanded in the other. A consideration of the following sections will 

 illustrate our contention as to similarity of evidence. 



