scholarly journals Highly Metalliferous Potential of Framboidal and Nodular Pyrite Varieties from the Oil-Bearing Jurassic Bazhenov Formation, Western Siberia

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 449
Author(s):  
Kirill S. Ivanov ◽  
Valery V. Maslennikov ◽  
Dmitry A. Artemyev ◽  
Aleksandr S. Tseluiko

In the Bazhenov Formation, framboidal clusters and nodular pyrite formed in the dysoxic–anoxic interface within organic-rich sediments. Some nodule-like pyritized bituminous layers and pyrite nodules are similar to pyritized microbial mat fragments by the typical fine laminated structure. Framboidal pyrite of the Bazhenov Formation is enriched in redox-sensitive elements such as Mo, V, Au, Cu, Pb, Ag, Ni, Se, and Zn in comparison with the host shales and nodular pyrite. Nodular pyrite has higher concentrations of As and Sb, only. Strong positive correlations that can be interpreted as nano-inclusions of organic matter (Mo, V, Au), sphalerite (Zn, Cd, Hg, Sn, In, Ga, Ge), galena (Pb, Bi, Sb, Te, Ag, Tl), chalcopyrite (Cu, Se) and tennantite (Cu, As, Sb, Bi, Te, Ag, Tl) and/or the substitution of Co, Ni, As and Sb into the pyrite. On the global scale, pyrite of the Bazhenov Formation is very similar to pyrite from highly metalliferous bituminous black shales, associated, as a rule, with gas and oil-and-gas deposits. Enrichment with Mo and lower Co and heavy metals indicate a higher influence of seawater during formation of pyrite from the Bazhenov Formation in comparison to different styles of ore deposits. Transitional elements such as Zn and Cu in pyrite of the Bazhenov Formation has resulted from either a unique combination of the erosion of Cu–Zn massive sulfide deposits of the Ural Mountains from one side and the simultaneous manifestation of organic-rich gas seep activity in the West Siberian Sea from another direction.

1981 ◽  
Vol 18 (4) ◽  
pp. 708-723 ◽  
Author(s):  
R. I. Thorpe ◽  
Jayanta Guha ◽  
Jules Cimon

Twenty-three lead isotope analyses are reported for massive sulfide deposits, the main copper–gold shear zone deposits in anorthosite of the Doré Lake complex, and two gold deposits, all in Archean terrane, in the Chibougamau district. Five analyses were also obtained for lead occurrences in Proterozoic carbonate sediments in the Mistassini Basin.Galenas from the Coniagas and Lemoine deposits of volcanogenic massive sulfide type, from the Taché Lake deposit of possibly the same type, from the Norbeau and Ayrhart gold properties, and one from within the Opemiska mine, have Archean compositions. Of these, the Lemoine, Norbeau, and Opemiska mine galenas are slightly younger than the others or were contaminated during later deformation and (or) metamorphism.Analyses for the main Cu–Au deposits generally form a cluster, although the spread in 206Pb/204Pb ratios is significant and three analyses for the Copper Rand deposit, in particular, are distinct from data for the other deposits. One interpretation is that the data, in combination with the Archean analyses, define a secondary isochron reflecting a primary age of Archean deposits and rocks at 2735–2800 Ma and a secondary event, including genesis of the Cu–Au ores, at 2240–2160 Ma. Additional evidence for a metamorphic–plutonic(?) event at about 2200 Ma has been provided by previous paleomagnetic studies. One galena from the Opemiska deposit appears to have had uranogenic lead added at 1735–2075 Ma. Three analyses of galena from the Campbell (Merrill) pit are anomalous or indicate they were formed at 162–300 Ma, and it is suggested they may have resulted from multiple episodic additions of ambient rock lead to galena originally deposited at about 2200 Ma.Two new analyses, together with four older values, for Mistassini Basin lead occurrences define a possible secondary isochron that may indicate an integrated source age of 2655 or 2940 Ma at mineralization ages of 2100 and 1700 Ma, respectively. This secondary isochron is very poorly defined because three other new analyses plot above the line.This study suggests that further geochronological investigation of the Cu–Au orebodies, and of felsic dykes that occur in many cases in close spatial association with them, should be undertaken.


2013 ◽  
Vol 109 (1) ◽  
pp. 1-9 ◽  
Author(s):  
P. Mercier-Langevin ◽  
H. L. Gibson ◽  
M. D. Hannington ◽  
J. Goutier ◽  
T. Monecke ◽  
...  

2010 ◽  
Vol 46 (5-6) ◽  
pp. 585-614 ◽  
Author(s):  
Reinaldo Sáez ◽  
Carmen Moreno ◽  
Felipe González ◽  
Gabriel R. Almodóvar

2021 ◽  
pp. 36-47
Author(s):  
Tatyana SERAVINA ◽  
Svetlana KUZNETSOVA ◽  
Ludmila FILATOVA

The article describes composition of the host rocks and ores of the Lazursky and Maslyansky polymetallic volcanogenic massive sulfide deposits of the Lazursky ore field located within the Zmeinogorsk ore region of the Rudny Altai minerogenic zone. The ore field is composed of various facies of the Devonian (Late Givetian – Frasnian) ore-bearing siliceous-terrigenous basalt-rhyolite formation containing horizons of synvolcanic metasomatites. All rocks of the ore field were subjected to folding and schistosity with zones of tectonic brecciation. Hydrothermal alterations are represented by carbonatization and chloritization. The ore bodies exposed at the Lazursky and Maslyansky ore deposits are represented by copper-pyrite, copper, and zinc-copper-pyrite massive sulfide ores and other varieties. The major ore minerals of the deposits are chalcopyrite, pyrite, sphalerite, marcasite, and pyrrhotite.


2020 ◽  
Vol 47 (1) ◽  
pp. 1 ◽  
Author(s):  
Marcelo García ◽  
Jorge Correa ◽  
Víctor Maksaev ◽  
Brian Townley

The seabed included in the Chilean Exclusive Economic Zone (EEZ) has proper conditions to originate and host different ore deposits, but its geological knowledge is scarce and scattered. The existent studies are very limited in terms of geochemical and mineralogical analyses. The most significant non-energetic mineral resources off Chile correspond to Fe-Mn nodules and crusts, phosphorite deposits, gold and titanium placer deposits and massive sulfide deposits. Fe-Mn nodule sites occur in abyssal plains and seamounts, and around volcanic islands, at depths from 2,890 to 4,332 m, and can contain important concentrations of Cu and Ni (up to 1.38% Cu+Ni) and Co (up to 0.53%). Co-rich Fe-Mn crust occurrences have been reported around the Rapanui and Salas y Gómez islands, with Cu+Ni contents up to 0.3%. Phosphorite sites occur in Holocene sedimentary beds of the continental shelf off Peru and northern Chile, with P2O5 average content of 22.6%. Gold placer deposits are found in beaches and channels of southern Chile and may extend offshore probably in submarine canyons. Titanium placer deposits have been evaluated in different beaches of Chile and could also be continued offshore. Platinum anomalies have been found in channels and bays of southernmost Chile. No samples of Volcanogenic Massive Sulfide (VMS) mineralization are known in the Chilean EEZ to date. However, samples of hydrothermal vents, with potential for polymetallic VMS type mineralization, have been recovered around the Rapanui Island, and several seamount and volcanic island chains indicate favorable conditions for formation and preservation of these ore-deposits. The available geological information on the seabed of the Chilean EEZ is insufficient to estimate the real potential of its non-energetic mineral resources.


1977 ◽  
Vol 14 (11) ◽  
pp. 2440-2452 ◽  
Author(s):  
Karen Stamatelopoulou-Seymour ◽  
Wallace H. MacLean

Base metal and gold ores in thin calc-silicate and cordierite gneiss units at Montauban-Les-Mines have historically been described as pyrometasomatic deposits related to granitic intrusions. They are stratigraphically overlain by quartzo–feldspathic gneiss and amphibolite, the uppermost amphibolite unit being a pillowed metabasalt.Chemical analysis shows all the amphibolites to be derived from basic igneous rocks, probably basaltic flows or shallow intrusives. Some analyses of quartzo–feldspathic gneisses follow igneous trends on variation diagrams and plot closely with those of indisputable volcanic rocks associated with massive sulfide deposits from the Kuroko District, Japan, and Noranda, Quebec. They appear to be metamorphosed intermediate to acidic volcanic tuffs and associated sediments, and are thus termed 'leptites'.The volcanic environment of the ore deposits, their general conformability to stratification, and other distinguishing features, strongly suggest they may be exhalite deposits formed in the overlapping carbonate–sulfide facies.


1976 ◽  
Author(s):  
J. S. Stacey ◽  
B.R. Doe ◽  
L.T. Silver ◽  
R.E. Zartman

2019 ◽  
Vol 946 ◽  
pp. 169-173
Author(s):  
A.A. Biryukova ◽  
T.D. Dzhienalyev ◽  
A.V. Boronina

The purpose of the work is the obtaining of magnesium silicate ceramic proppants, based on ultrabasic overburden rocks of Kempirsai deposits of chromite ores (Kazakhstan). The chemical and mineralogical composition of ultrabasic overburden rock was studied by chemical, microscopic and X-ray diffraction analyzes. It is established that the main mineral of ultrabasic overburden rocks is serpentine, present in the form of fibrous chrysotile and lamellar antigorite. In the impurities are iron oxides and hydroxides, chrome spinel, carbonates, quartz. Assessment of the use of overburden rocks as a raw material for the production of ceramic proppants was carried out. The sintering interval of overburden rocks was determined at 1280-1300 °C. The sintering firing optimum temperature of ceramics, based on this type of raw material is 1300 °C. It is established that to harden the structure of magnesium silicate ceramic it is necessary to activate the raw material thermally at a temperature of 1000 °C. The influence of binder type on the properties of magnesium silicate proppants, based on the Kempirsai serpentinites was studied. Magnesium silicate proppants, based on ultrabasic overburden rocks, were obtained with the following properties: apparent density – 1.6 g/cm3, strength resistance (52 MPa) – 14%, sphericity and roundness – 0.8; chemical resistance (hydrochloric acid) – 98%, static strength of the fraction 16/20 - 72–118 N/granule. The field of application is oil and gas production, metallurgy and ceramic industries.


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