186 The N.Z. Journal of Science and Technology. [May 
in the associated greensand on a former seashore line or in the shallow 
water immediately off it. 
On the ridge north of the bridge the nodular layer is apparently absent, 
though it may be hidden by the covering of soil. 
The escarpment continues westward on the south side of the river, and 
is characterized by marked variations in its lithological character. It is 
always more or less glauconitic, and in some cases the amount of siliceous 
material is very great. In places there are numerous worm-borings in 
calcareous greensand filled with glauconitic material. Some of these are 
pinkish in colour, slightly harder than the matrix, and at times worm- 
casts make up 50 per cent, of the bulk of the rock. Although these 
are decidedly phosphatic, the amount of impurity, such as quartz and 
glauconite, which they contain is too high for the rock to be considered as 
a source of phosphatic limestone. 
Farther on, between the Waihao Forks and Waihao Downs Railway- 
stations, the limestone is apparently more glauconitic, some layers 
being almost a greensand in character, and specially is this the case in 
the lower levels and as the beds are traced in the direction of the 
Downs Station. The greensands are here full of the remains of worm- 
borings and what look like the casts of fish-intestines, some of them 2 ft. 
in length, 1 \ in. thick, elliptical or flattened in cross-section, with peculiar 
transverse curvilinear marking, which is not spiral, however. They show 
a marked reaction for phosphate, and also when broken exhibit the 
peculiar and characteristic surface appearance of phosphatized limestone, 
are slightly pinkish in colour, but are composed essentially of calcareous 
greensand. 
There is an increase in greensand as one approaches what was apparently 
the direction of the old shore-line, as indicated by the greywacke 
mass, a mile and a half north of the Waihao Forks Station—a south¬ 
easterly extension of the greywacke stripped surface. The upper 
layers are less glauconitic, but nevertheless must be classed as little 
better than a calcareous greensand. Individual bands more completely 
hardened, and forming at times irregular and discontinuous projections 
on the surface, give promising indications of phosphate, the increased 
hardness being probably due to its presence. The whole section between 
the two railway stations is characterized by the most pronounced current 
bedding. 
The most promising locality for the occurrence of phosphatic limestone 
in payable quantities lies in a small gully on the south side of the Waihao 
River, about a mile from the Forks Station. Here there is a thick massive 
band, 15 ft. in thickness, and exposed for 300 yards on the steep rocky 
faces of the gully. It is hard and glauconitic, with pinkish fracture, and 
consisting largely of the class of material which east of McCullough’s Bridge 
forms nodules and which closely resembles the material of the harder bands 
near Waihao Downs. The layers pass into one another gradually, and 
there is no sign of the presence of the band of shell-fragments and nodules 
with occasional rolled pebbles which is met farther east. This locality was 
in the middle of the Waihao marine area when the beds were deposited. 
The bed above mentioned probably represents an upper level of Waihao 
limestone. No sign of the nodular layer was observed at the mouth of the 
gully where the beds are in close association with the underlying green¬ 
sands, which were as fully developed as in the lower levels farther east 
near McCullough’s Bridge. 
