Bulletin, Issues 28-29Geological Survey of Western Australia, 1907 - Geology |
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90 feet abandoned abandoned).-This alluvial amphibolite andesite angle appears average battery belt Bulletin carried chains chloritic considerable quantity country rock crosscut Cuddingwarra cyanide Darlot Day Dawn diabase diorite distance district driven Duke of York dyke eastward Epidiorite epidote Extended feet in length feet in thickness feet in width feet level feet north feet south felsites felspar Felspar porphyry Fingall fissure flat foliated footwall Gold crushed Gold therefrom Golden Goldfield granite grano-diorite greenstone Hill hornblende inches junction Lady Mary Lawlers line of reef lode main shaft main vertical shaft miles Mines Name and Number north-easterly north-west northward Number of Lease ounces outcrop Photo porphyry Princess Ada pyrites quartz reefs reef strikes schist schistose shoot showing the Yield stoped surface Table showing tons of stone underlay shaft veins vertical depth Victory United water level westward whilst Wilson's Patch winze Zoisite
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Page 11 - ... colour of polarisation. In the saussuritic parts the almost colourless zoisite is at times accompanied by slightly larger grains of greenish-yellow epidote. In these aggregates the partially preserved polysynthetic twinning of the former felspathic substance is often seen forming a kind of background. The existence of garnet, scapolite, or of any zeolitic mineral in this saussurite could not be proved. Zoisite occurs in the form of independent crystals in the rock mass, as well as in the saussuritic...
Page 9 - Qoczel-s report of 1S95, who was at that time Field Geologist to the Government, and had visited this district in 1894 : — Northwards from the Lake Austin depression and rising as we proceed in that direction extends the Cue-Day Dawn basin, in which the two central townships of the...
Page 31 - ... alteration. This type appears to pass imperceptibly into the fine-grained foliated and schistose varieties, which in hand specimens are of the usual type, and which, seen under the microscope, consist of a finely granular mixture of hornblende and felspar with a good deal of magnetite, the whole showing considerable crashing, but being very little altered [7115]. These greenstones are intersected by occasional granite dykes, these being apparently merely offshoots from the main body. One or two...
Page 45 - ... Quartz. It probably results from the alteration of a soda-line felspar. Ore Deposits. Reefs and Lodes. — The reefs in this district are nearly all normal quartz reefs, but with one or two exceptions are small and of no length. Short lenticular reefs of white glassy quartz are fairly common, but these are all apparently too poor to pay. The general strike of all the reefs is about north and south, and almost all of those which have been opened up contain copper, often in considerable quantity;...
Page 11 - Well-marked stickensides are frequently found in the vein-matter. The zone of decomposition of the reef matter extends to very different depths in the different mining districts. In Cue, for example, it extends to a depth of from 60 to 70 feet, in the Menzies and Kalgoorlie districts to an average of from 130 to 180 feet, but even within the same mining district the depth will be found to vary. The country rock is generally decomposed to quite the same depth as the veins themselves. The reefs are...
Page 53 - Ywld of the Zangbar. Table showing the Yield of the Filbandint. St. George, GML 273. — Very little work was being done on this property at the time of my visit, though a good deal has been •carried on in the past and a lot of gold has been taken out, principally from one very rich shoot, from which some 10,000nzs.
Page 26 - This is a very fine-grained black rock in which small spicules of felspar only are clearly visible to the unaided eye. Under the microscope it is seen to be composed of a...
Page 11 - In the amphibolite from the Emperor Mine, quartz and felspar are found intermixed in such a manner as to form 'a very pretty graphic granite. Here and there larger portions of felspar are saussurised, and are replaced in the section by spots which appear of a dull white colour in diagonal light. Under the microscope these are seen to consist of an aggregate of irregularly disposed prisms and grains of zoisite, which, when of larger dimensions, show very distinct cleavage, straight extinction, and...
Page 7 - Lookout, another apparently disconnected diorite l«iss is found, with numerous granite dykes intruding and the associated (j'.i.'irtz reefs. The' granite dykes in this locality are coarse grained, and can clearly be seen to consist of quartz, orthoclase felspar and mica. The mica, however, occurs in two forms, the Muscovite (common white mica), and Lepidolite (lithia mica).