Page image

a—l 3

28

(6.) Te Anau Series. —These rocks are confined to the Upper Matakitaki and Glenroy Valleys. The rocks consist of coarsely agglomerated red and green breccias, masses of which are to be met with in the coarse alluvial gravels of the Horse Terrace,, and elsewhere in the Matakitaki Valley. Mr. Cox describes these beds as being in the Upper Glenroy associated with serpentine. Metamorphic. Mica Schists. Upper Middle and Lower Schists. —From the Mikonui to the northern slopes of Mount Alexander and Bell Hill, the triple series of schists have been distinguished, traced, and described.* North-east of the Ahaura the same rocks form a series of ranges, flanking the higher mountains of the main ranges more to the east. They are continued across the sources of the Big Grey into the Upper Buller, and to the north-east they terminate within the Matakitaki Watershed. Associated with the lower beds there is an extensive development of crystalline limestone, which forms an isolated mountain on the left bank of the Maruia, at the junction of the Alfred, and nearly opposite the Bog Saddle leading into the valley of the Brown Grey. These are overlain by dark mica schists, which by Cox are called " Carbon schists," these being followed by " black calcareous slates, passing upwards into foliated quartzose schists, talc- and chlorite-schists, and fine-grained mica-schist." In the southern part of the district these beds pass upwards into a dark-coloured semi-metamorphic slate, probably of Devonian age. Bands and belts of mica schist occur amongst the gneissic and granitic rocks of the Victoria and Brunner Mountains on the east side of the Inangahua Valley, and of the Paparoa Mountains on the west side of the valley. These, however, will be described as part of the gneissic series with which they occur interbedded. Quartz reefs occur in these beds, but none are being worked for gold within the area dealt with in this report. Gneissic Schists. (a.) Crystalline Schists and Metamorphic Granite. —This formation, as developed and displayed within the northern district of Westland, has already been described.! What are practically the same rocks are. continued to the north-east throughout the length of the district presently under consideration. At the source of the Inangahua the continuation of the larger connected area of these rocks turns in direction to the north, and continues in a broad belt along the Victoria and Brunner Mountains to the Gorge of the Buller at the Lyell. The great bulk of the rocks in these mountains is gneissic and granitic, but mica schists are at places largely developed, as, for instance, at the upper forks of Larry's Creek, and at some places on the Maruia slope of the mountains, where it is reported there are considerable areas of slate rock ; from which it is to be inferred that mica schist is the rock meant, though not indicated. In the Paparoa Mountains these rocks, especially in the southern part, are mostly gneissic— even granitic gneiss being of rare occurrence. In the valley of Bough Biver there are some rather important bands of mica schist. Towards the central northern higher part of the range the rocks are more granitic ; but north of the Nile Valley to the Buller Gorge the western slopes of the range are, to a large extent, schistose, a large percentage of these rocks in the Totara Valley being of a schistose character and often characteristic mica-schist. The isolated areas that appear on the coast-line from Cape Foulwind to Bazorback have their chief developments at Cape Foulwind, between the Nile and Fox Bivers in the Charleston District; and there are one or two outcrops of less extent farther to the south. At Cape Foulwind the bulk of the rock is porphyritic granitoid gneiss, often a simple gneiss. At Charleston, the rocks are gneiss and mica schist; and further south of the same general character. Although an extensive examination of these rocks was made during the past season in the region of the Paparoa Mountains, they do not appear to yield minerals of a valuable description, and, in fact, appeared to be remarkably barren of metallic minerals, or of vein stuff generally. In the Victoria and Brunner Mountains there is possibly a greater hope of finding metallic or mineral riches of some kind; but, even amongst these mountains, prospecting from Larry's, from Boatman's, and from Beefton has not resulted in the discovery of anything particularly noteworthy. Plutonic. Massive and Intrusive Granites. —ln northern Westland such rocks are found along the western margin of the granite crystalline rocks, while in the Paparoa Mountains they are confined to an isolated patch at Barrytown, and a number of veins of coarse-grained granite exposed in the Buller (Lower) Gorge. In the Victoria and Brunner Mountains, especially on their eastern slopes, intrusive granites extend along the range, and cross the Buller Biver between the Lyell and Fern Flat. These are well shown in many sections between the Lyell Township and the junction of the Maruia with the Buller. The granite rocks in the Upper Matakitaki were not closely studied, nor those that lie on the east side of the Maruia Valley, and from the basement-rocks of the range between the middle part of that valley and that of the Matakitaki. No minerals of value have been discovered in these rocks. Massive quartz-reefs are said to occur in the Greenstone Mountains, and one is noted on the map of Westland as occurring on the higher part of Turiwhate. This outcrop of quartz is said to be of great size. The geological map accompanying includes the area of Northern Westland examined during 1893, the map being designed to illustrate another report dealing with the entire area. The Under-Secretary for Mines. Alex. McKay.

* Goldfields and Mining Reports, 1893, p. 172. j Goldfields and Mining Reports, 1893, p. 173.

Approximate Cost of Paper. —Preparation, not given; printing (2,450 copies), £21 9s.

By Authority: Samuel Oostall, Government Printer, Wellington.—lB9s, Price Is.J

Log in or create a Papers Past website account

Use your Papers Past website account to correct newspaper text.

By creating and using this account you agree to our terms of use.

Log in with RealMe®

If you’ve used a RealMe login somewhere else, you can use it here too. If you don’t already have a username and password, just click Log in and you can choose to create one.


Log in again to continue your work

Your session has expired.

Log in again with RealMe®


Alert