scholarly journals Geology and geochemistry of the Sleeper gold-silver deposit, Humboldt County, Nevada; an interim report

1989 ◽  
Author(s):  
J.T. Nash ◽  
W.C. Utterback ◽  
J.A. Saunders
Keyword(s):  
Silver Deposit ◽  
Interim Report ◽  
Humboldt County ◽  
Gold Silver

scholarly journals Mineragenic Position and Geological Potential of Technogenic- Mineral Formations of the Gold-Silver Deposit Valunistoe (Сhukotka Autonomous Region)

2021 ◽  
Vol 20 (2) ◽  
pp. 172-191
Author(s):  
V.N. Goldyrev ◽  
◽  
V.A. Naumov ◽  
O.B. Naumova ◽  
◽  
...  
Keyword(s):  
Industrial Development ◽  
Mineral Resources ◽  
Silver Deposit ◽  
Mineral Formation ◽  
Secondary Mineral ◽  
Chemical Parameters ◽  
Useful Components ◽  
Gold Silver ◽  
Solid Part ◽  
Physical And Chemical

In the coming years, the mine of LLC "Rudnik Valunisty" developing the gold and silver Valunistoe and Gornoye deposits will exhaust economically justified reserves. One of the ways to extend the life of the mine and increase the profitability of production should be the extraction of man-made secondary mineral resources. The purpose of the study is to identify the main types of solid and hydromineral form of technogenic-mineral formations at the Valunistoe Deposit, as well as to estimate the possibility of their industrial development. The useful components content was determined and calculated. The results of theoretical modeling of physical and chemical parameters of hypergenic mineral formation of the solid part of technogenic-mineral formations are shown. Objects of formation of technological waters are given. The conditions of concentration of gold and other metals are considered.

Age and Genesis of the Pokrovskoe Gold–Silver Deposit (Russian Far East)

2021 ◽  
Vol 62 (1) ◽  
pp. 134-143
Author(s):  
A.A. Sorokin ◽  
A.Yu. Kadashnikova ◽  
A.V. Ponomarchuk ◽  
A.V. Travin ◽  
V.A. Ponomarchuk
Keyword(s):  
Russian Far East ◽  
Far East ◽  
Volcanic Complex ◽  
Silver Deposit ◽  
Volcanic Zone ◽  
Granitoid Magmatism ◽  
Gold Silver ◽  
Igneous Complexes

Abstract ––We present results of geochronological studies of rocks from different igneous complexes and of hydrothermally altered volcanics with Au–Ag mineralization from the Pokrovskoe deposit. The age of the ore-hosting granites of the Sergeevsky pluton of the Upper Amur complex is estimated at ~129 Ma. The primary age of dacites of a sill-like body is within 128–125 Ma and is close to the age of volcanics of the Taldan complex. Propylitization processes superposed on these dacites are dated at ~122–119 Ma. Taking into account the commercial contents of gold and silver in these rocks, we believe that the age of the hosted orebodies is in the same interval. The period 122–119 Ma is also the time of formation of the Gal’ka volcanic complex in the Umlekan volcanic zone, which was accompanied by granitoid magmatism. This suggests that the formation of the Pokrovskoe deposit was associated with the accumulation of the Gal’ka complex.

Chapter 21: Geology of the Fruta del Norte Epithermal Gold-Silver Deposit, Ecuador

2020 ◽  
pp. 431-450
Author(s):  
Stephen Leary ◽  
Richard H. Sillitoe ◽  
Jorge Lema ◽  
Fernando Téliz ◽  
Diego Mena
Keyword(s):  
Base Metal ◽  
Late Jurassic ◽  
Volcanic Rocks ◽  
Silver Deposit ◽  
Epithermal Gold ◽  
Mountain Ranges ◽  
The North ◽  
Pull Apart Basin ◽  
Gold Silver ◽  
A Minor

Abstract Fruta del Norte is a completely concealed and extremely well-preserved, Late Jurassic epithermal gold-silver deposit of both low- and intermediate-sulfidation type, which is located in the remote Subandean mountain ranges of southeastern Ecuador. Currently defined indicated resources are 23.8 million metric tons (Mt) averaging 9.61 g/t Au and the total endowment is 9.48 Moz Au. The deposit, notable for the widespread occurrence of visible gold and bonanza grades, will be bulk mined underground. Fruta del Norte was discovered in 2006 during greenfield exploration and systematic drill testing of a conceptual geologic model, which predicted that auriferous veins would occur in andesitic volcanic rocks inferred to underlie a zone of arsenic- and antimony-anomalous silicification in fluvial conglomerate. The host andesitic volcanic rocks, crosscutting feldspar porphyry, and associated phreatic breccia are part of a roof pendant in the Zamora batholith. Together, they are products of a continental-margin volcanoplutonic arc of Middle to Late Jurassic age. The deposit lies beneath the northern extremity of the ~16-km-long, Suárez pull-apart basin where it is localized by steep, second-order faults within the regionally extensive Las Peñas strike-slip fault zone. The pull-apart basin was progressively filled by fluvial conglomerate, dacitic ignimbrite, finer grained siliciclastic sedimentary rocks, and, finally, andesite flows. The Fruta del Norte deposit comprises a 1.3-km-long and up to >300-m-wide vein stockwork associated with quartz-illite-pyrite alteration. The deposit comprises two principal vein types, one in the south dominated by quartz, manganoan carbonates, and abundant base metal sulfides and the other in the north dominated by manganese- and base metal-poor quartz, chalcedony, and calcite. Adularia is a minor gangue mineral in both. Both vein types are abruptly transitional upward and westward to a third important ore type characterized by intense silicification and chalcedony veining, with disseminated and veinlet marcasite (± pyrite). An extensive silica sinter horizon directly overlies the andesitic rocks and/or occurs as interbeds in the lowermost 20 m of the conglomerate and, consequently, is in unusual proximity to the underlying gold-silver orebody. Much of the conglomerate lacks silicification except for a narrow, steeply inclined zone exposed above the deposit, which led to its discovery.

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