Features of ore formation of gold deposits of Glukharinsky District (Prikolyma Terrain)

2019 ◽  
Vol 484 (1) ◽  
pp. 66-70
Author(s):  
A. A. Biryukov ◽  
A. V. Volkov ◽  
K. Yu. Murashov ◽  
A. A. Sidorov
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Gold Deposits ◽  
Ore Formation ◽  
Reducing Conditions ◽  
Isotope Studies ◽  
Enclosing Rocks ◽  
Ore Deposition

This study discusses new data on the isotopy of δ34S, δ18O, microelements, and rare earth elements (REE) in the Au deposits of the Glukarinsky ore cluster. The identified geochemical features are indicative of the reducing conditions of ore deposition, participation of magmatogenic fluid in ore formation, and the enclosing rocks being the possible sources of ore material. Isotope studies indicate that the ore-forming fluid has a mixed, metamorphogenic–magmatogenic composition. The obtained results make it possible to qualify the examined objects as Au deposits associated with granitoid intrusives.

scholarly journals GEOCHEMICAL FEATURES OF ORES AND HOST ROCKS OF THE MALO-TARYNSKY OROGENIC GOLD DEPOSIT (VERKHOYANSK-KOLYMA FOLDED AREA, NORTHEAST RUSSIA)

2020 ◽  
Vol 39 (5) ◽  
pp. 41-55
Author(s):  
L.I. Polufuntikova ◽  
◽  
V.Y. Fridovsky ◽  
N.A. Goryachev ◽  
◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Gold Deposit ◽  
Wall Rock ◽  
Northeast Russia ◽  
Ore Formation ◽  
Reducing Conditions ◽  
Host Rocks ◽  
The Eu ◽  
Ore Zones

The paper presents the results of studying the distribution of major, rare, and rare earth elements in the terrigenous rocks, wall-rock metasomatites, and ore zones of the orogenic Malo-Tarynsky gold deposit (Upper Kolyma folded area, Northeast Russia). Hydromicatization, carbonatization, sulfidization, and silicification played an important role in the formation of metasomatites and ore zones leding to different mobility of macroelements with a predominance of acidic low-temperature carbonic-calcium metasomatism. Increase in the proportion of quartz in wall-rock metasomatites and ore zones involved the loss of the most of the rock-forming elements: К, Na, Al, Fe, Mg, and Тi, and Ca and CO2 were supplied. The ores and metasomatites of the deposit are characterized by As-Au-Sb-W geochemical specialization with low Bi, Co, Ni, Cr, Cu, and Zn and high Li, Ag, Cd, and Sc concentrations. The distribution spectra of REE contents in modified rocks are similar to that of REE in Upper Triassic host rocks showing some tendency to decreasing their amount. The removal of rare earth elements during the formation of metasomatites and ores was established. The values of the Eu/Eu* (0.61–0.88) and Ce/Ce* (0.6–1.3) anomalies indicate slightly reducing conditions of the ore formation with a limited involvement of oxidized meteoric water.

scholarly journals Peculiarities of the distribution of rare-earth elements in the ores of some gold deposits of Eastern Transbaikalia

2018 ◽  
pp. 48-58
Author(s):  
B. N. Abramov
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Gold Deposits ◽  
Volatile Components ◽  
Magma Chambers ◽  
Eastern Transbaikalia ◽  
Different Depths ◽  
Degree Of Differentiation ◽  
Gold Sulfide ◽  
Ree Patterns

The distribution of rare-earth elements (REE) in ores of gold deposits of East Transbaikalia has shown that the ore-bearing magma chambers have different depths and degrees of differentiation. The greatest degree of differentiation was within the magmatic foci (Eu/Eu* — 0,29—0,32; Rb/Sr — 0,98—1,40), which are the sources of gold-quartz-arsenopyrite ores, the magmatic sources of the gold-quartz and gold-sulfide-quartz ores (Eu/Eu* — 0,53—0,72; Rb/Sr of 0,10 to 0,54) had lesser degree of differentiation. Magma chambers that are sources for the gold-quartz-arsenopyrite ores (Eu/Sm — 0,08—0,14), were at shallower depths than those for gold-quartz and gold-sulfide-quartz ores (Eu/Sm — 0,11—0,19). The formation of gold-quartz-arsenopyrite ores took place at the magma chambers, largely enriched in volatile components, it is indicated by the existence of a significant tetrad effects in REE patterns of (T1-4 - 0,80; 1,15; 1,16).

Fractionation of Rare-Earth Elements in the Processes of Hydrothermal Ore Formation

2018 ◽  
Vol 73 (5) ◽  
pp. 451-456
Author(s):  
M. V. Borisov ◽  
D. A. Bychkov ◽  
N. F. Pchelintseva ◽  
E. A. Ivleva
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Ore Formation

Mobility of Uranium, Thorium and Lanthanides Around the Bangombe Natural Reactor (Gabon)

1994 ◽  
Vol 353 ◽  
Author(s):  
R. Bros ◽  
F. Gauthier-Lafaye ◽  
P. Larque ◽  
J. Samuel ◽  
P. Stille
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Clay Minerals ◽  
Nuclear Reactor ◽  
Black Shales ◽  
Weathering Profile ◽  
The Core ◽  
Reducing Conditions ◽  
Isotopic Studies ◽  
Textural Evidence

AbstractNew mineralogical and isotopic studies were carried out on samples from the Bangombé natural nuclear reactor. This reactor is located at shallow depth in the weathering profile and has been subjected to severe supergene alteration. Textural evidence indicates partial dissolution of uraninite in the Bangombé ore related to precipitation of Fe-Ti oxi-hydroxides and clay minerals (kaolinite and metahalloysite). As a consequence of the alteration of the uraninite, uranium and f issiogenic rare earth elements were released in the clayey border of the reactor, whereas radiogenic 232Th remained confined in the close vicinity of the core. A retention effect is also evidenced, under reducing conditions, in the black shales located above the reactor.

scholarly journals SILVER IN THE GOLD DEPOSITS OF THE AMUR REGION

2021 ◽  
pp. 130-136
Author(s):  
NATALIA VALENTINOVNA MOISEENKO ◽  
◽  
SVETLANA MIKHAILOVNA AVRAMENKO ◽  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Negative Correlation ◽  
Gold Deposits ◽  
Amur Region ◽  
Positive Correlation ◽  
Lead And Cadmium ◽  
Native Silver

The main minerals of native silver hubs on gold deposits of the Amur region (Albyn, Malomyr, Pioner, Pokrovskoe) were studied. It has been established that silver has a positive correlation with gold, zinc, arsenic, antimony, lead and cadmium. There is a negative correlation of silver with zirconium, yttrium, hafnia, tantalum and rare earth elements.

GEOCHEMICAL FEATURES OF NATIVE GOLD AS DIRECT SIGNS OF ORE FORMATION LODE AND ALLUVIAL GOLD OCCURRENCE TYPES

2020 ◽  
pp. 22-31
Author(s):  
S. A. Milyaev ◽  
G. G. Samosorov ◽  
S. V. Yablokova ◽  
L. V. Shatilova ◽  
N. N. Pozdnyakova
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Gold Deposit ◽  
Native Gold ◽  
Element Distribution ◽  
Igneous Rocks ◽  
Sulfide Mineralization ◽  
Ore Formation ◽  
Alluvial Gold ◽  
Geochemical Indicators

The features of impurity element distribution in native gold of two ore formation gold deposit types are con- sidered. A typomorphic set of elements for gold-polysulfide-quartz and gold-quartz low-sulfide mineralization was determined. Geochemical indicators for estimating ore formation types of native gold are offered. The differences in gold composition due to metallogenic specialization of regions are established. Data on the distribution of rare-earth elements in native gold are obtained, which allows to predict igneous rocks composition during gold-polysulfide-quartz deposit formation.

scholarly journals Significance of Calcite Trace Elements Contents and C-O Isotopic Compositions for Ore-Forming Fluids and Gold Prospecting in the Zhesang Carlin-Like Gold Deposit of Southeastern Yunnan, China

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 338
Author(s):  
Jiasheng Wang ◽  
Jinyang Chang ◽  
Chao Li ◽  
Zhenchun Han ◽  
Tao Wang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Gold Deposit ◽  
Meteoric Water ◽  
Gold Mineralization ◽  
Mining Area ◽  
Gold Deposits ◽  
Hydrothermal Fluids ◽  
Magmatic Fluid ◽  
Isotopic Compositions

The Zhesang gold deposit of southeastern Yunnan is an important component of the Dian-Qian-Gui (Yunnan, Guizhou, and Guangxi) “Golden Triangle”, which hosts a multitude of Carlin-like gold deposits (CLGDs). Calcite is one of the most common gangue minerals in Zhesang. The calcites that have been found in the mining area are classified as ore-stage and post-ore calcites. The ore-stage calcite exhibits a clear paragenetic relationship with gold-bearing arsenopyrite and with an alteration halo that has been cut by the post-ore calcite. To elucidate the origin of the ore-forming fluids of the Zhesang gold deposit and to investigate the possibility of utilizing calcite geochemistry as prospecting indicators, the rare earth elements (REEs), Y, Fe, Mn and Mg contents, and C-O isotopic compositions of calcites from Zhesang have been analyzed. The ore-stage calcite is enriched in middle rare earth elements (MREEs) relative to light rare earth elements (LREEs) and heavy rare earth elements (HREEs) (MREE/LREE = 1.11–1.61, MREE/HREE = 6.12–8.22), whereas post-ore calcite exhibits an enrichment in LREE (LREE/HREE = 4.39–14.93, MREE/LREE = 0.35–0.71). The ore-stage and post-ore calcites were both formed by hydrothermal fluids; however, these hydrothermal fluids may have different sources. The Fe contents of the ore-stage calcite are significantly higher than those of post-ore calcite (4690–6300 μg/g versus 2030–2730 μg/g). Ore-stage calcite also has significantly lower δ18OV-SMOW values than post-ore calcite (11.03–12.49‰ versus 16.48–17.14‰). These calcites with an MREE/LREE ratio greater than 0.92, MREE/HREE ratio greater than 5.69, Fe content greater than 3827 μg/g, and δ18OV-SMOW value less than 14.40‰ represent ore-stage calcites and are important prospecting guidelines. According to the REE, C-O isotopic characteristics of the calcites and the previous findings, it is inferred that the ore-forming fluids of the Zhesang gold deposit were a mixture of crustal fluid by meteoric water leaching wall rocks and a small amount of basic magmatic fluid. The formation of post-ore calcite might be derived from meteoric water and marine carbonates interaction. The ore-forming fluids of the Zhesang gold deposit may be associated with the intrusion of diabase that outcrops in the mining area, and that the basic magmatic activities of the Indosinian period also provided some of the ore-forming materials and heat for gold mineralization.

Textural and geochemical characteristics of garnet from the Luoyang Fe skarn deposit, eastern China: implications for ore-forming fluid evolution and mineralization conditions

2021 ◽  
pp. 1-14
Author(s):  
Qiang Wang ◽  
Yu-Long Yang ◽  
Yao Tang ◽  
Wen-Qi Guo ◽  
Tian-Xin Xiao
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
First Generation ◽  
Southern China ◽  
Eastern China ◽  
Magmatic Fluid ◽  
Reducing Conditions ◽  
Metallogenic Belt ◽  
Two Generations ◽  
Heavy Rare Earth Elements

Abstract The late Palaeozoic Yong’an–Meizhou depression belt is an important iron (Fe) and polymetallic metallogenic belt in southern China. It has undergone a transformation from Tethys to the circum-Pacific tectonic domain. The Luoyang deposit is one of the typical Fe skarn deposits in the Yong’an–Meizhou depression belt of eastern China. Garnet is a characteristic mineral in the deposit. Two generations of garnets are detected in the deposit based on their textural characteristics and trace-element contents, and are represented by Fe-enriched andradite. The first generation of garnets (Grt1) have two types of garnets (Grt1-A and Grt1-B). Type A garnets of the first generation (Grt1-A) (Adr80-88) replaced by massive diopside-magnetite assemblage exhibit distinct oscillatory zonings and display patterns of enriched light rare earth elements (LREE) to weak heavy rare earth elements (HREE), with weak negative to positive Eu anomalies, and highest U, ΣREE and Sn contents. Type B garnets of the first generation (Grt1-B) are irregular zones (Adr94-96) coexisting with magnetite, in which Grt1-A is generally dissolved, and have obviously LREE-enriched and HREE-depleted patterns, with weak negative to positive Eu anomalies, and moderate U, ΣREE and Zn contents. Garnets of the second generation (Grt2) (Adr96-99) that replaced massive magnetite together with sphalerite show unzoned patterns, with a flat REE pattern and pronounced negative Eu anomalies as well as contents of lowest U and ΣREE, and highest W. The substitution of REEs in garnets occurs as [X2+]VIII –1[REE3+]VIII +1[Si4+]IV –1[Z3+]IV +1in an Al-enriched environment. Luoyang hydrothermal fluids shifted from reducing conditions with relatively high-U and -ΣREE characteristics to oxidizing conditions with relatively low-U and -ΣREE characteristics. The reduced siderophile elements and increased fO2 in fluid during Grt1-B formation caused magnetite mineralization and reduced Zn contents during Grt2 formation, causing the deposition of sphalerite. All garnets formed from magmatic fluid and were controlled by infiltrative metasomatism in an opened system.

Fractionation of rare-earth elements in the processes of hydrothermal ore formation

2018 ◽  
pp. 59-64
Author(s):  
M. V. Borisov ◽  
D. A. Bychkov ◽  
N. F. Pchelintseva ◽  
E. A. Ivleva
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Maximum Amount ◽  
Hydrothermal Solutions ◽  
Ore Formation ◽  
Distribution Of Elements ◽  
Sharp Growth ◽  
Ree Fractionation ◽  
Host Rocks ◽  
North Ossetia

Data on the distribution of elements across the Pb-Zn section of the Gatsyrovskaya vein (Upper Zgid, North Ossetia, Russia) showed that during the formation of the vein significant changes in the spectra of rare-earth elements (REE) occur in ore samples. The sharp growth of ratios LaN/YbN, LaN/NdN, GdN/HoN, and GdN/YbN is confined to the vein intervals, where the maximum amount of ore components is deposited. A comparison of the REE spectra of ores with the characteristics of the spectra of the near-vein and host rocks suggests that the deposition of the vein material occurred from solutions whose compositions with respect to the REE varied with time. REE fractionation occurred due to the mobilization of components by hydrothermal solutions during their reaction with the host Paleozoic granites.

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