1919.] 
Departmental Eeports. 
395 
junction. This seam possibly is the large seam outcropping in the latter 
stream. Several other smaller seams were also observed in the section 
exposed along the'Mangaawakino. 
Mangangarongaro .-—The Mangangarongaro enters the Mokau from the 
north about twenty-three miles by river from the sea. The mine from 
which the bulk of the coal was obtained in the Mokau district is at this 
point. It is stated that 7 ft. of coal occurred in the mine, but in this thick¬ 
ness was included a clay or shale band which varied from 6 in. to 3 ft. An 
outcrop of 15 chains above the mouth of the Mangangarongaro shows 3 ft. 
of coal overlain by sandstone and underlain by 4 ft. of carbonaceous clay, 
with sandstone again below. This outcrop is about 30 ft. above sea-level, 
and belongs to a seam higher in the sequence than the seam worked. 
A mile up the Mangangarongaro a section shows in downward sequence— 
(1) Shale of unknown thickness ; (2) carbonaceous shale, 3J ft. ; (3) coal, 
2\ ft. ; (4) shale, 3| ft. ; (5) coal, 4 ft. ; (6) shale, 8 ft. The 4 ft. coal- 
seam is 230 ft. above sea-level. A thick shale band outcropping on a terrace 
20 chains east of the mouth of the mine and 170 ft. above it is evidentlv 
on the same horizon as the beds in the above section. The shale band here 
contains only streaks and pockets of coal. 
Other coal-outcrops were observed in the Mangangarongaro, but all 
were small. The rocks throughout strike in a north-westerly direction, and 
dip gently to the south-westward. 
Mangakawhia .—The Mangakawhia, a stream of moderate size, enters 
the Mokau from the north half a mile above the confluence of the Manga¬ 
ngarongaro. It has cut deeply into the coal-measures. At intervals over 
a distance of 30 chains from the river a coal-seam 3 ft. to 4 ft. thick shows 
at or near the top of the cliff bordering the stream on the ’eft. This seam 
at 20 chains from the mouth of the Mangakawhia is on fire. It is overlain 
and underlain by sandy shale. 
Near the head of Coal Creek, a branch entering the Mangakawhia from 
the east from Ohinewhero Hill, is a section showing five seams of coal, in 
upward sequence respectively 2 ft., 6J ft., 2Jft., 2 ft., and 4 ft. thick, and 
contained in 200 ft. of strata. The 6J ft. seam is underlain and overlain 
by thick beds of friable sandy shale, and includes a band of carbonaceous 
shale. 1 ft. thick. The 4 ft. seam, which is overlain by soft massive sand¬ 
stone, rests on friable shale. 
In addition to the outcrops mentioned above other outcrops belonging 
to a seam or seams in an horizon 150 ft. to 250 ft. lower in the sequence 
were observed at several points in the Mangakawhia Valley. The largest 
outcrop showed less than 2 ft. of coal. 
Mangatoetoe .—In the Mangatoetoe, which enters the Mokau from the 
north-east a few chains above the Mangakawhia, three coal-seams were 
observed. The lowest outcrop, about 30 chains from the mouth of the 
stream, shows 6 ft. of clean coal contained within thick beds of friable shale. 
Another seam, 3J ft. thick, about 25 ft. higher in the sequence, outcrops 
at the foot of a waterfall a few chains farther up-stream. The floor of this 
coal is soft shale, and the roof massive sandstone. A third seam, still higher 
in the sequence, and 4 ft. to 5 ft. thick, outcrops in the creek-bed one mile 
and a half from the river. It rests on soft sandstone, and is overlain by 
20 ft. of friable shale and claystone. 
Near Mangatoi Homestead .—On the banks of the Mokau, from near 
the mouth of the Mangangarongaro to beyond Mangatoi Homestead, coal 
outcrops at many points. The seams to which some of these obviously 
belong have already been described. 
Stockman’s Mine is on the north side of the Mokau, close to Mangatoi 
Homestead. It consists of a single adit driven 450 ft. on a seam 44 ft. 
