Metamorphic belts are complex regions where accretion or collision has added to or thickened continental crust Goldrich deposits can be formed at all stages of orogen evolution so that evolving metamorphic belts contain diverse gold deposit types that may be juxtaposed or overprint each other
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ABSTRACT GOLD DEPOSITS IN METAMORPHIC ROCKS WHAT WE KNOW AND WHY ARE WE GETTING MORE CONFUSED Richard J Goldfarb Department of Geology and Geological Engineering Colorado School of Mines 1516 Illinois Street Golden Colorado 80401 USA Orogenic gold deposits represent the main source of gold in the world’s deformed Phanerozoic
Gold is most often found in very small amounts mixed with other materials Experienced gold prospectors rarely look for gold but rather look for rocks and rock formations that are known to hold gold
Gold deposits are found in a variety of geological conditions identifying these indicators of gold geology will increase your likelihood of finding gold
The shear zone related gold ores are hosted especially by the medium grade metamorphic rocks of the socalled Getic Realm largely developed in the Sebeş Căpăţâna Leaota and Făgăraş Mts
Gold transport and concentration are most commonly suggested to be associated with metamorphic processes as indicated by the volatile composition of the hydrothermal fluids the progressive decrease in concentration of elements enriched in the gold deposits with increasing metamorphic grade of the country rocks and the common association of
Therefor gold is usually found in metamorphic rocks that have been affected by hydrothermal solutions Finally I may add that in addition to its presence in metamorphic rocks sometimes gold gets weathered out Then because of its large density gold gets transported by streams and concentrated into what are called placer deposits
Distribution of Gold Ill • Igneous Rocks By DAVID GOTTFRIED JACK ROWE and ROBERT I TILLING GEOLOGICAL SURVEY PROFESSIONAL PAPER 727 An investigation of the abundance and distribution of gold in plutonic and volcanic rocks of diverse magma types and tectonic settings UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON 1972
Gold is found in rocks of the Piedmont Plateau a belt of metamorphic rocks extending from New York to South Carolina The metal occurs as grains wires or sheets in quartz veins and along mineralized fault zones in the surrounding metamorphic rocks
GOLD IN METAMORPHIC ROCKS FACTS AND FANCY Fig 1 – A possible fractallike classification of mineral deposits in which the shear zone related ores have a symmetrical position to the “intermediate” ore deposits such as porphyry coppers or massive sulfide deposits acc to Uduba¿a et al 1998
Gold Deposits in Metamorphic RocksPart I Gold in the United Verde Massive Sulfide Deposit Jerome Arizona By ED DEWITT and JEROME WAEGLI The AlaskaJuneau and Treadwell Lode Gold Systems Southeastern Alaska By THOMAS D LIGHT DAVID A BREW and ROGER P ASH LEY US GEOLOGICAL SURVEY BULLETIN 1857
Feb 10 2020 · Years of geologic research have shown that orogenic gold is usually hosted in metamorphic rocks This does not mean that all metamorphic rocks have orogenic gold or that every mountainbuilding event leads to gold deposits It just means that the orogenic gold that has been found was found in metamorphic rocks
Gold deposition is accompanied by carbonation sulphidation and muscovitebiotite alteration where the host rock is of suitable bulk composition The correlation of major gold deposits with rock type even when the gold is primarily in veins argues for rock‐dominated depositional systems not
The abundance of gold in crustal rocks is an important constraint on the formation of gold deposits Gold concentrations in unmineralised igneous sedimentary and metamorphic rocks range from 0·05 to 20 ppb with average concentrations commonly between 0·5 and 5 ppb