396 The N.Z. Journal of Science and Technology. [Dec. 
thick. The coal, which is clean and hard, is overlain by massive sandstone, 
and rests on compact sandy claystone. About 40 ft. above the adit, and 
in the small creek from which it is driven, is an outcrop of a seam 2J ft. 
thick. The coal rests on shale, but the roof was not seen. On the river- 
edge, about 15 ft. above sea-level and 30 ft. below Stockman’s seam, coal of 
unknown thickness (at least 2 ft.) appears from beneath shaly clay. What 
is probably Stockman’s seam outcrops at points a few chains up-stream and 
down-stream from this point. The thickness of the down-stream outcrop 
was 4 ft., but that of the up-stream outcrop was not observed. The same 
seam shows on the left bank of the Mokau immediately above the mouth of 
the Mangapohue. It is here 4 ft. thick. The seam overlying Stockman’s 
outcrops a few chains up the Mangapohue, showing 2 ft. of coal. Another 
seam 5 ft. in thickness, of which nearly a half is carbonaceous shale, outcrops 
about 50 chains farther up-stream in an horizon about 100 ft. higher. It 
lies between beds of sandy shale. 
Mangatoi .-—The Mangatoi is a small branch of the Mokau entering 
from the right about a mile above Mangatoi Homestead. Near the top 
of the cliffs bordering the stream, on its left side, and at a point 30 chains 
from the river, are two seams, the upper 3 ft. and the lower 4 ft. thick. 
They are separated by 15 ft. of shale, and rock of a similar nature overlies 
the upper seam and underlies the lower. These seams are more than 300 ft. 
above the stream-bed. About 200 ft. lower is a third seam, 2 ft. thick, 
which rests on soft shale and is overlain by massive sandstone. 
In Te Maire Creek, which enters the Mokau 40 chains above the mouth 
of the Mangatoi, are four seams, two of 2 ft. and two of 1 ft. 
Wade Creek .—Wade Creek, or the Mangamahaki, is a stream of moderate 
size which enters the Mokau from the right. It drains part of the high, 
broken, heavily wooded country north of Ohinewhero Hill. The coal- 
measures in this locality are high above the level of the river and the 
principal valleys. Coal 5J ft. thick outcrops 800 ft. above the valley-bottom 
of a right-hand branch of Wade Creek. It is contained between thick 
beds of friable shale, and about 2J ft. of rather impure coal is included in 
the above thickness. Fragments of coal in a slip indicate that a higher 
seam exists in this locality. Along the same spur, 15 chains eastward, a 
seam of dirty coal 3 ft. thick with no bottom showing is exposed in a slip. 
The containing strata are shale. This probably belongs to an horizon below 
that of the last-mentioned seam. 
It is evident that a large amount of coal exists in the basin of the Mokau 
River. The larger seams, however, being associated with beds of a soft 
friable nature, will be expensive to work in most areas. The localities to 
which this disadvantage does not apply are Stockman’s mine, the old mine 
near the Mangangarongaro-Mokau junction, and the neighbourhood of the 
large outcrop in Ivaipaku Creek. In Stockman’s mine the roof in the adit, 
which is from 12 ft. to 16 ft. wide, is perfectly sound, although it has been 
standing several years and was never timbered. It is said that practically 
no timber was used in the old mine. Unfortunately the clean coal in this 
mine is nowhere more than 6 ft. thick, and is usually not more than 4 ft. 
In Stockman’s the seam does not average more than 4J ft. Again, the silt 
and timber deposited during the big flood of 1914 blocked the river-channel 
below these mines even to launch traffic except at high tide or during floods. 
Even if the channel were cleared it would be again blocked by the first high 
flood. 
The seam exposed in the bed of the Kaipaku is undoubtedly worth 
more attention than any other observed. An exposure 3 chains in length 
shows an average thickness of over 7 ft. of clean hard coal. Both roof and 
