76 Transactions. 



No nodules r borings are present on the line of junction, which is indistinct 

 one rock gradually passing into the other. 



Along the escarpment to the south-west the same general features are to 

 be observed, the Amuri limestone being decidedly glauconitic at times and 

 the greensand layer at the junction more marked than near the gorge, 

 while the Weka Pass stone exhibits in places the typical facies, though in 

 others it is like the Amuri limestone, and in others again it is of sandy 

 texture, approaching a freestone, and is so friable that it can be rubbed into 

 powder with the fingers. 



At the point where shells of Pecten huttoni are found in the Weka Pass 

 stone, which is a few chains east of the low part of the escarpment where 

 the road crosses, the junction presents the usual features of worm-borings 

 and the presence of scattered dark phosphatic nodules, while on the 

 weathered surface of the Amuri limestone there are small protuberances of 

 limestone, evidently more resistant than the remainder of the rock, and 

 owing their preservation to the presence in them of an amount of calcium 

 phosphate in excess of that in the surrounding rock. 



When traced west the limestone outcrop passes over into the water- 

 shed of Boby's Creek, and in the bed of its most northerly tributary an 

 excellent exposure is to be seen. This is as follows : — 



(1.) Amuri limestone, the upper 3 ft. bored more and more till the 

 junction is reached, the borings being filled with greensand. 

 Detached fragments of more phosphatized limestone occur along 

 the junction. The limestone is here much thinner than it is on 

 the escarpment to the north-east, and thins out still more when 

 followed to the south-west towards Mount Grey. 



(2.) Nodular layer : This consists mostly of detached fragments of 

 limestone, the true nodules being small ; all are enclosed in a 

 greensand matrix. A well-rounded pebble of greywacke was 

 found embedded near the junction, indicating in all probability 

 the close proximity of a shore-line. This passes up into 



(3.) Greensand, with fewer and fewer nodules. 



(4.) Weka Pass stone, more glauconitic than usual, as is usually found as 

 the deposits approach an outstanding greywacke mass ; in this 

 case it is that of Mount Grey. In the lower part of this layer 

 shells of Pecten huttoni were found in a somewhat poor state of 

 preservation. 



The strike of all the beds is north-east and south-west, with a dip to 

 the south-east of 35°. 



No evidence of unconformity, excepting the pebble, is given by this 

 locality, although it affords ample opportunity for locating one did it exist. 

 The interstratification of glauconitic limestone in the Amuri stone indicates 

 that no great change in depth occurred between the deposit of the typical 

 Amuri limestone and the Weka Pass stone, the interstratification of the 

 glauconitic material in the former preparing the way for the final develop- 

 ment of the pronounced glauconitic type. 



North-east Slope of Mount Grey. 



The fine escarpment which runs south-west through Mount Brown 

 towards Mount Grey is deflected when it reaches the vicinity of the mass 

 of greywacke of which the latter is composed, no doubt partially owing 

 to earth-movements, of which there is decided evidence in the locality. 



