GEOLOGICAL SURVEY.

Wellington Independent, Volume XVI, Issue 1703, 25 February 1862, Page 5

GEOLOGICAL SURVEY.

(Frum the Wanganui Chronicle.) The Hon. Mr. Crawford's party returned from the exploration of the country lying between the Rangitikei and Wauganui rivers on Friday last, the 14th. inst.

The rocks of the Rangitikei were found to be essentially the same Tertiaries as those of the Wanganui, and therefore the inference is, that that they are continuous between those two rivers. They extend from the Rangitikei to the flanks of the Ruahine, also trom Patea (a district in Rangitikei) to the north and in the direction of Napier as far as the eye can reach. Tertiary rocks were still found from Fatea to within about ten miles from the base of Ruapehu, [where igneous products replaced them. Abreast of Ruapehu, and about 10 miles to the eatward of its base, a powerful range rises, evidently of slaty or Grauwaoke rocks, and proceeds in a N. N, E. direction, towards the Bay of Plenty. This range ought to be examiued, but it lies principally in the province of Auckland. It is called the Kaimauawa. The avalanche which carried away the Waugaehu bridge was found to proceed almost from the top of Ruapehu, whence it swept broatisido into the Wangaehu, and so dowu tbe river.

At Tokanu, ou Lake Taupo, the party was detained for a week by constant thunder storms and rain. They then proceeded by the Rua Mata plains, to the head of the Wanganui; which they struck on the right bank. In the bed of the Waipare, a tributary of the Wanganui, they found slaty rock in situ, thereby probably proving the base rock to the westward of the volcanic range. The first sedimentary rocks found at the head of the Wanganui, Mr. Crawford ven-s tures to call the coal shales. There i e every reason to suppose that they ar tertiary, and lhat the coal will prove good gas coal. These shales underlie stratum of limestone, a few feet thick containing undoubted tertiary fossils, an > which is supposed to be the base of thd base of the blue shale. The rock of the Rangitikei, which Mr. Crawford supposes to be the equivalent of the coal shales of the Wanganui, yields a cardium or escalop, wbich ia supposed to be clearly tertiary. It will thus be seen that the only country traversed, where there was a possibility of finding gold, copper, or other minerals of that kind, was the Kaimauawa range, and the slaty rock of the Waipare; but it is quite possible that the slaty flooring may be found to crop out at or near the surface in some parts of this district. The gorge of the Rangitikei appears to be extremely difficult of access, and for want of supplies aud assistance, Mr. Crawford was unable to attempt it. There is every reason to suppose that the coal shales underlie this settlement immediately under the arenacous limestone at the base of the blue shale.

The natives were very civil, and appear to be well disposed, but they are much taken up with Runangas; and on the Wanganui river, with eating lizards. A detention of three days was incurred at the head of the Wanganui, waiting for a canoe.

If Mr Crawford is right in supposing, the slaty rock of the Waipare to be the base rock of this part of tbe island, it is then the rock on which the Tertiaries rest here, and may be metaliferous; but it is needless to think of sinking to find metals, unless they crop out at or near the surface; which, as the altered and slaty rooks of these islands are folded, undulating, and never horizontal, is by no means improbable. But even in that case, how many chances are ther against finding metals, even should they exist.