Page:Transactions NZ Institute Volume 9.djvu/611

This page has been proofread, but needs to be validated.
566
Transactions.—Geology.

The upper part of this formation is the lowest and oldest shown on the sections. It crops out on the shores of Lake Waikaremoana, forming low white cliffs, and partaking of the same dip as the superincumbent sandstones and gritstones. In its lithological characters it somewhat resembles the Papa Rocks, to be described further on, but is much harder and whiter, and contains in places peculiarly-shaped cement stones or septaria, which, owing to the weathering of the clay in which they are embedded, often stand out in grotesque forms.

I only saw fossils in one spot, and regret that I was unable to procure any of them.

Waikaremoana Sandstones.

Lying conformably on these clayey strata are a series of very hard sandstones and gritstones, having a probable thickness of over 2,000 feet. These sandstones form the Panikiri and Matakuhia ranges, most prominent features, rising in one long slope of 20° from the east, to a maximum height of 3,905 feet above the sea, and then suddenly descending on the western face 1,900 feet, nearly perpendicularly, to the shores of the Lake. The prevailing colour is greyish-white where exposed to the action of the weather, but when in the form of boulders, as seen in the river beds, it is a rich dark brown. The stratification is well marked, the beds dipping to the southeast at angle of 20°. The hardness and sharpness of these sandstones is such, that they will probably be used at some future date as grindstones and sharpening-stones, and also for the purpose of flagging, for which they are well adapted, as slabs may be obtained often of ten feet square and from six to eight inches in thickness.

They form most picturesque groups on the shores of the Lake, where broken by joints and fissures, which are generally filled with a rank growth of vegetation, conspicuous amongst which is the graceful Beech tree (Fagus), which in the higher parts of the mountains forms large open forests. In the month of February on these trees is often to be seen a very handsome Scarlet Mistletoe, which I have seen nowhere else.

The western line of outcrop of the sandstones may be traced for many miles to the north-east of Waikaremoana in a succession of bold precipitous bluffs facing the north-west.

The Lake itself lies at the foot of these mountains, and is about eleven miles long, with an average width of two miles, its greatest breadth being opposite the Constabulary Station of Onepoto, where it is four miles across. It is acknowledged by all who have seen it to be by far the most beautiful of all the Lakes of the North Island. The grandeur of the bluffs of the eastern side, rising as they do at Ohiringi 1,100 feet perpendicularly out of the water, is unsurpassed by anv cliff scenery I am acquainted with; whilst