Age dating of host rocks and gold deposits of the Carolina Slate Belt ..... 12 11. Mineralogies and textures of three types of selected gold deposits in the Carolina Slate Belt..... 13 12. Evidence in ore textures for the presence of early epithermal gold mineralization ..... 14 13. Evidence in volcanic rock textures for the presence of early epithermal gold mineralization ..... 15 14. Fluid ...
You've heard me talk elsewhere about "country rock" or host rock, which is the most prevalent underlying rock (including bedrock) in any given gold-bearing locale. In areas where auriferous quartz veins are found some of the most common host rocks are:
Host rock is, simply, the rock surrounding the ore deposit. Host rocks, as the definition suggests, may be found as a host to any kind of ore deposit, from gold to uranium. Host rock may also be defined as the type of rock where mineralization occurs. Host rocks are significant in identifying the
Fig. 2 shows an example of gold-bearing veins in altered felsic tuff from the Hatu gold deposit (west Junggar, Xinjiang); all gold-bearing veins are accompanied by strong alteration in the wall-rocks characterized by quartz, sericite, calcite and chlorite, which coexist with abundant pyrite and arsenopyrite.
The average gold content of sedimentary rocks in parts per million is sandstone and conglomerate, 0.03; normal shale, 0.004; and limestone, 0.003. Certain graphitic shales, sulfide schists, phosphorites, and some types of sandstones and conglomerates may contain up to 2 ppm Au or more.
Unlike alluvial gold, which is found as very small flakes on river banks, gold-bearing rocks have to be dug out of the ground. We want pure gold, but gold-bearing rocks include lots of other materials such as quartz, calcite and the sulfides of other metals. We need to separate the gold from everything else in the rock so the rock needs to be treated in some way.
Numerous world-class porphyry copper-gold deposits are hosted by high-K or shoshonitic intrusions, such as Bingham copper-gold mine in USA, Grasberg copper-gold mine in Indonesia, Northparkes copper-gold mine in Australia, Oyu Tolgoi copper-gold mine in Mongolia and Peschanka copper-gold prospect in Russia.
Capsule Geology: Twelve alkalic porphyry copper-gold deposits are known to occur within the Galore Creek syenite complex. This complex comprises a series of Late Triassic to Early Jurassic orthoclase-porphyry syenitic bodies which have intruded coeval Upper Triassic Stuhini Group volcanic rocks and related sediments.
Alluvial Gold and Eluvial Gold.... Knowledge That Can Help You To Make a Huge Gold Find. Just What is Primary, Alluvial Gold and Eluvial gold. Primary gold is Reef or Lode gold where the gold is still deposited in its original host rock.
This assumes that the Bridge River host rocks are the same age as the ultramafic rocks. The timing of emplacement of the ultramafic bodies either by intrusion or faulting is gauged by the presence of chromite in the sedimentary record assuming that the ultramafic rocks are …
Veins and reefs of gold-bearing quartz can occur in many types of rock, for example around granites, in volcanic rocks or in regions of black slate, but in most cases these host rocks are not the immediate source of the gold.
host rocks, irrespective of the PT conditions and of the affected rock types. Very obvious is the influence of fluids on the metamorphic rocks, e.g. the case of metasomatic ores hosted by limestones and micaschists from the Rodna ore
host rock an overview ScienceDirect Topics. The host rocks are sedimentary rocks of the MarquetteBaraga Supergroup ... have produced similar rapid and pervasive silicification before significant decay, ..... basic observed relationships in host rocks and the gold deposits they contain.
Volcanogenic massive sulfide ore deposits, also known as VMS ore deposits, are a type of metal sulfide ore deposit, mainly copper-zinc which are associated with and created by volcanic-associated hydrothermal events in submarine environments.
When you decide to prospect for diamonds, learn to recognize diamond and then watch your gold pan to see if you trap any of these gems. Diamond has a specific gravity of 3.5, and will concentrate with black sands in a gold pan.
Mesothermal gold deposits form half way up through the rise of the melt from the deep crust to the surface usually at a depth of less than 10 km but greater than 1 km. temperatures at these depths are generally somewhere between 450 degrees and 250 degrees Celsius.
Schist is often the host rock for a variety of gemstones that form in metamorphic rocks. Gem-quality garnet, kyanite, tanzanite, emerald, andalusite, sphene, sapphire, ruby, scapolite, iolite, chrysoberyl and many other gem materials are found in schist.
2009-06-08· Gold is a very rare and precious metal that is soft, malleable and heavy, and it is often found with other minerals, such as quartz. Learn about the differences between gold and fool's gold with ...
Volcanic Minerals . Can your knowledge of volcanic rocks make you rich? Yes!! That is, if you combine it with knowledge of mineral deposits and global economic factors. Volcanoes directly or indirectly produce or host deposits of aluminum, diamonds, gold, nickel, lead, zinc, and copper. We use most of these materials everyday and, over the course of a lifetime, consume some of them (via the ...
Gold is predominantly associated with deformed quartz veins hosted within an envelope of highly strained and hydrothermally altered rock oblique to the host volcanic stratigraphy. Less commonly, gold is found in replacement-style disseminations within altered basalts along and proximal to contacts with interflow iron formations or ultramafic sills transected by the eastern splay of the D1 gold ...
Origin of the Host Rocks and Mineralization of the North Lake Gold Deposit, La Ronge Domain, Saskatchewan 1 E.G. Appleyard2 Appleyard, E.C. (1994): Origin of the host rocks and mineralization of the North Lake gold deposit, La Range Domain, Saskatche
The effort to understand the geology of gold was perhaps man's first serious effort at understanding the earth's rocks and minerals. Gold is actually a relatively scarce element on the crust of the earth, but it occurs in trace quantities spread throughout many different kinds of rocks and in many different geological environments.