Page:Transactions NZ Institute Volume 15.djvu/477
Besides which there are numerous small seams, 10 inches thick and less, occurring in the jurassic strata in various localities, as the Hokanui Hills and Mataura, Southland; Waikawa, Otago; and the Waikato Heads, Auckland; in fact wherever the formation occurs, but since they have never been found in seams which are of sufficient thickness to work remuneratively they do not merit any special attention.
Bituminous Coals.—These coals are, so far as is at present known, exclusively confined to the west coast of the South Island. At Collingwood they occur as thin seams from 27 inches to 32 inches in thickness; one mine being at present at work in this district. The average composition of the coal from this locality is—
| Fixed carbon | 53.29 |
| Hydro-carbon | 38.18 |
| Water | 2.06 |
| Ash | 6.47 |
| 100.00 |
At Westport seams of bituminous coal occur from 4 feet to 50 feet in thickness, and two mines are at present at work. The estimated quantity of coal in this field, from accurate surveys, is 140,000,000 tons, which is probably considerably below the mark. All the coal is level, free, and generally at an elevation of from 1,000 to 3,000 feet above the sea. The average composition of the coal is—
| Fixed carbon | 63.81 |
| Hydro-carbon | 31.88 |
| Water | 3.08 |
| Ash | 1.23 |
| 100.00 |
There are also two small areas of highly-inclined, faulted coal, which is much crushed, and too tender to be marketable. It has the following composition:—
| Fixed carbon | 75.05 |
| Hydro-carbon | 21.29 |
| Water | 1.40 |
| Ash | 2.26 |
| 100.00 |
Two mines have been opened to work this coal, but both are now abandoned.
At Greymouth another series of bituminous coals has been worked in which the percentage of fixed carbon is considerably less than in that from Westport. It is, however, an exceedingly valuable gas coal, and the coke made from it is as good as can be procured. The seams vary in thickness