Bulletin, Nummers 1-10Geological Survey of Western Australia, 1898 |
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amphibolites assay auriferous Authority bands beds belt Bore carbonates Carboniferous cement cent chlorite clay Colony conglomerate considerable consists containing Coolgardie Coolgardie Goldfield copper country rock Creek crosscut crushed diorite distance district dollied and specimens dwts dykes East extending feet level felsite ferruginous field foliated formation galena Gold Mining Lease Gold therefrom Goldfield Government Geologist granite H. P. Woodward Hill hornblende inches ironstone Irwin River Kalgoorlie Kanowna kaolin Kimberley Lake limestone lode main shaft mica miles mineral Murchison Goldfield Nature of Strata North and South North-East North-West Nullagine occur outcrop Perth Phillips River Pilbarra portion Previous to 1897 pyrites quantities quartz reefs quartzites Range Report River sand sandstone schists seam shale silica South-East stone strike summit of Mount surface tellurium thence thickness tons cwt Total Trace underlie vertical depth West Western Australia width Wongan Hills Yield of Gold
Populaire passages
Pagina 8 - Illustrations of Comparative Anatomy, Vertebrate and Invertebrate, for the Use of Students in the Museum of Zoology and Comparative Anatomy. Second Edition. Demy 8vo. cloth, is. 6d. A Catalogue of Australian Fossils (including Tasmania and the Island of Timor), by R.
Pagina 35 - ... pug" or bedded kaolin, and in the underlying much-weathered chlorite schists, from which it has doubtless been originally derived. It is either so thoroughly intermingled with the clay as to be inseparable from it, or else is found in lumps or lining vughs in a soft mammilated form, with a bright grey metallic lustre. It occurs also in the nodules of magnesite found at the junction of the "pug
Pagina 57 - ... solutions have found a comparatively easy passage. The width of the ore bodies reaches as much as 80 feet in places. The gold occurs free as tellurides and as auriferous pyrrhotite. The free gold presents such characters as point to its having been derived from the oxidation of the tellurium-bearing minerals; the decomposition of the auriferous pyrites may also be the source of some portion of it. The free gold often occurs in spongy or cellular masses of varying sizes and shapes, and is at times...
Pagina 66 - ... mineral in the granite. Recent developments have shown the existence of extensive deposits of sandstone lying beneath the ubiquitous ironstone gravels. These sandstones, which are usually of a light grey colour, are fine-grained and of an even texture. The maximum thickness attained by the sandstone is not less than 150 feet. The quartz reefs all occur in the granite to the west of the diorite, always in close proximity to the junction of the two rocks. The general strike of the reefs is a little...
Pagina 80 - The conglomerate covered a much larger area than it at present occupies, and denudation has gone on to a large extent since it formed part of one continuous formation. The thickness of the conglomerate is nowhere very great, operations having shown that it rarely, if ever, exceeds 20 feet. The conglomerate is not of sedimentary origin, but has apparently been formed by the alteration in situ, and" subsequent cementation of the underlying rocks.
Pagina 28 - ... slope to the flat, one may notice somewhat regular lines of round boulders and pebbles roughly marking the outcrops of the conglomerate beds. By these indications, and also by following up the runs of alluvial gold until they stopped all along certain horizontal lines, the auriferous conglomerates were originally located and worked by prospectors by means of drifts and tunnels.
Pagina 4 - ... diorite that it is impossible to distinguish it in a broken specimen. The rocks of this belt are a good deal broken and faulted by granite and diorite dykes, and quartz lodes containing gold, iron and copper. There are also some large magnesia lode-masses, rich in fine gold, which will probably prove to be serpentine at a depth. Many of the lodes also contain large quantities of chlorite.
Pagina 28 - Three classes occur ; 1st, the alluvium of existing creeks ; 2nd, the alluvium of older creek beds, but in conjunction with the present streams ; 3rd, older alluvial deposits or deep leads bearing no relation to existing streams or configuration of the country. . . The older alluvial deposits are found" in the river flats, where the auriferous gutters are crossed and recrossed by the present streams.
Pagina 57 - ... mineral-bearing solutions have found a comparatively easy passage. The width of the ore bodies reaches as much as 80 feet in places. The gold occurs free as tellurides and as auriferous pyrrhotite. The free gold presents such characters as point to its having been derived from the oxidation of the tellurium-bearing minerals ; the decomposition of the auriferous pyrites may also be the source of some portion of it. The free gold often occurs in spongy or cellular masses of varying sizes and shapes,...
Pagina 57 - As a general rule the ore deposits have no well-defined walls, but seem to pass insensibly into the surrounding rock. The lodes are often traversed by a network of quartz veins, which ramify in all directions. There is abundant evidence attesting the fact that the rocks have been subjected to profound dynamic phenomena, which has resulted in the production of lines of weakness along which mineral-bearing solutions have found a comparatively easy passage.