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It is here where the minerals are found in this crumbly chlorite, and generally in geodes that is, the faces of the minerals all point inward, formerly a spherical mass rough and uncouth on the outside, and from half an inch to nearly a foot in diameter. These are valuable finds, and well worth digging for.
As I looked over this ice-belt, losing itself in the far distance, and covered with its millions of tons of rubbish, greenstones, limestones, chlorite, slates, rounded and angular, massive and ground to powder, its importance as a geological agent, in the transportation of drift, struck me with great force.
All that has been found of any great beauty has been in the western end of the Shaft No. 1 and the eastern of Shaft No. 2, where the trap is quite soft; here it is found nearly every day in greater or less quantity, and from this some may generally be found on the dump, or, in the vein of chlorite which I mentioned as a locality for the dogtooth spar, considerable may be obtained in it and on its western edge near the ceiling.
The hill immediately over our camp was Bullabalakit, and consisted partly of granular felspar, probably tinged greenish with chlorite; and partly of concretionary porphyry, the concretions being mottled red and white, and containing grains of quartz and crystals of common felspar; the white concretions resisting the action of the atmosphere stood in relief on the weather surface; I noticed also a vein of amethystine quartz.
In the little stream were many pebbles of vesicular trap, probably an amygdaloid with the kernels decomposed, but containing particles of olivine; also pebbles of a syenitic compound, consisting of quartz, hornblende, and felspar; and of compact felspar, mottled green and white, the green colour probably being due to chlorite or green earth, and they enclosed also decomposed crystals of mica and hornblende.
The rock formation of the hills upon its right continued of that chlorite schist which prevailed near Mr. Whaby's, which I have already noticed, and quartz still appeared in large masses, on the loftier ranges opposite, so that the geology of the neighbourhood could not be said to have undergone any material change.
From Yass Plains to the very commencement of the level interior, every range I crossed presented a new rock-formation; serpentine quartz in huge white masses, granite, chlorite, micaceous schist, sandstone, chalcedony, quartz, and red jasper, and conglomerate rocks.
As before stated tin will never be found far from granite, and that granite must have white mica as one of its constituents. It is seldom found in the darker coloured rocks, or in limestone country, but it sometimes occurs in gneiss, mica schist, and chlorite schist.
Apparently a vein of it would not be noticed at all from the surrounding rock of gravelly earth, but there it is, and in a vein of chlorite. This is so throughout the long and more or less complete stated lists of mineralogical localities.
The veins of chlorite are not so conspicuous, being of a dark-green color; but by probing along the walls with a stick or hammer, they may be recognized by their softness, or by its dull glistening appearance. They are comparatively few, but from an inch to three feet wide; and minerals are found by digging it out with a stick or a three-foot drill, to be had at the headings.
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