time been hewn and thrown over. We cannot, therefore, be surprised when, at the first locality in which we meet with these tertiary beds, at the edge of the basin in crossing the saddle at the northern slopes of Big Ben, we find them broken, distorted, and sometimes placed vertically. In the short interval of about 80 yards, in slips on the slopes of Big Ben, many strata are exposed, consisting of small seams of lignite, alternating with argillaceous or arenaceous shales, pipeclay, loose sands of different colours, all more or less impregnated with ferruginous matter, and in which strike and dip change constantly.

In a line from north to south, I noticed the following changes:—

Strike S.S.E. to N.N.W., dip towards E.N.E. 53 deg.
N. to S. E. 88
„ N.W. to S.E. „ N.E. 76
„ S.W. to N.E. „ S.E. 78

These are other changes which show us that the disturbances which have taken place at the edge of this basin area of the character usually occurring in lignitiferous and carboniferous beds, and that they have therefore not been occasioned by faults or throws as has been stated by persons on the spot.

This disturbance is hidden in many places by the detritus, which descends often in one continuous talus from the summits of Big Ben.

The altitude of the position of these disturbed beds above the centre of the basin or trough, confirms my theory still more strongly.

In descending towards this centre for about 200 feet, we observe a magnificent section in the first branch of McFarlane’s stream, which flows from Big Ben in a north-westerly direction. It is here that the seam of 4 ft. 7 in., which I examined two years ago, is exposed, and that the different pieces of land are situated, which have been bought by Mr. Thomas and the Kowai Coal Mining Company.

A remarkable feature in these beds is, that the whole are not only very much impregnated with sulphuret of iron, but that some of the deposits, consisting of loose sands, are full of a slight efflorescence of sulphur for which I cannot yet account, but which may almost lead us to the conclusion that they were deposited during volcanic eruptions in the neighbourhood, notwithstanding no other signs of such occurrences are to be found there. Looking at the constituents of the rocks which form this basin, the enormous quantity of sands which resemble the deposits of the same formation in the Malvern Hills is astounding.

As the deposition of the sands of the latter are derived from the decomposition of eruptive rocks, quartzose porphyries, &c., in the neighbourhood, and which now form but a very inferior portion of that zone, I am inclined to think that those of the McFarlane stream basin are also derived from the same source, although such rocks do not occur anywhere in the neighbourhood.

We must therefore assume that either the eruptive rocks, from which the sands in McFarlane’s basin were derived, have entirely disappeared from its neighbourhood, or that in the tertiary period the eruptive zone in the Malvern Hills was much higher and more extensive, being easily decomposed by the waves of the sea, which broke furiously against it, and above which its isolated masses stood as large islands.

At the same time we may presume, that the sea carried those sands in a westerly direction, and deposited them in deep fiords, or in shallow bays between high headlands, which, in tertiary times formed the eastern shore of the Middle Island of New Zealand.

In order to show what repeated changes have taken place, oscillations of level being, without doubt, one of the principal causes, I shall enumerate the different beds as they follow each other:

The following strata are noticed in a descending order, the seams of lignite are carefully measured, whilst the thickness of the other strata is only approximately given:

Reddish brown ferruginous shale...... forming often a hard conglomerate including layers and nodules of clay, or sandy iron ore .................. 2 0
Greenish loose sands, sometimes variegated .......... 3 6
Pinkish, sometimes variegated .......... 1 0
Greenish, yellowish do. .......... 3 0
Pinkish do. .......... 1 6
Greenish, darker do. .......... 6 9
Pink do. .......... 1 0
Greenish do. .......... 1 6
Sand, pinkish, sometimes compact and then more argillaceous, sometimes with a slight efflorescence of sulphur, and sometimes with remains of plants which have served for the deposition of clay iron ore .......... 31 0
Yellowish green loose sands, alternating with pink clays .......... 3 6
Sandstone, in some parts hard and compact, in others loose of a dark iron rust or greenish colour .......... 0 6
Bluish clays .......... 0 10
Sands partly reddish, partly pink or greenish, with a mixture of clay, sometimes forming a loose sandstone .......... 8 0
Variegated loose sands, not argillaceous 9 0
White loose quartzose sands .......... 2 3
Loose sands of different colours .......... 11 6
Dark slaty clays .......... 4 6
Green sands .......... 9 0
Oyster bed, consisting of very large specimens, the species identical with those of the lignitiferous beds of the Selwyn, very compact, but sometimes intermixed with small quantities of green and pink loose sands .......... 1 10
Sandy clays somewhat stratified .......... 3 0
Oyster bed, identical with the former .......... 1 3
Shale, sometimes very sandy .......... 4 9
Lignite inferior, and full of sulphuret of iron .......... 0 6
Grey pipeclays .......... 1 0
Greenish sands .......... 1 0
Dark grey clays .......... 1 0
The last three alternating .......... 4 0
Sands of different colours .......... 3 3
Shale .......... 2 0
Lignite .......... 0 8
Clays and shale, often sandy, with remains of plants, without doubt of marine origin, changed into lignite .......... 4 0
Lignite .......... 0 7
Sandy clays, sometimes shaly .......... 7 0
Clays and sands in different colours alternating .......... 15 0