Page:Picturesque Dunedin.djvu/104

92 voyages. The roof is hard coarse conglomerate, 70 feet in thickness, and auriferous, but not sufficiently rich to be workable. The floor is hard clay.

Until quite recently only three workable seams have been known to exist in the field; the uppermost 3ft. 6in, in thickness, and the main seam, 500 feet below, which has been already mentioned. About intermediate between the two is a 9ft. seam, which has not been worked. Within the last few months, however, a seam 19 feet in thickness has been discovered 150 feet below the main seam.

The average analysis of the Kaitangata coals is as follows:—

The total output from this field to the end of 1888, was 542,123 tons.

The Shag Point coal-field lies to the north, at a distance of about 35 miles, and has been worked for a number of years. The coal seams dip E.S.E. at 10 deg. below the sea, where they have been worked to a small extent, and where in all probability a very large deposit exists. Three seams have been worked, the maximum thickness having been about 12 feet, but they vary considerably both in thickness and in relative position. Quite recently a valuable seam is stated to have been met with, in a borehole, which was put down below what was the lowest known seam. The measures rise into the hills bordering the coast, and form an anticlinal arch, which is terminated to the westward by a syncline, from the base of which they again rise at high angles to Puke Iwitai. Out to landward side of the hills is a recently-established coalmine, from which the excellent fuel usual in the locality is obtained. According to late investigations by the Geological Survey Department, the field should extend to a considerable distance southward. Recently a number of samples of Shag Point coal have been analysed in the Colonial Laboratory Wellington, with the following results:—