Geology and isotopic composition of helium, neon, xenon and metallogenic age of the Jinding and Baiyangping ore deposits, northwest Yunnan, China

2003 ◽  
Vol 46 (8) ◽  
pp. 789-800 ◽  
Author(s):  
Chunji Xue ◽  
Yuchuan Chen ◽  
Denghong Wang ◽  
Jianmin Yang ◽  
Weiguang Yang ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Ore Deposits ◽  
Northwest Yunnan ◽  
Metallogenic Age ◽  
Helium Neon

Sulfur Isotopic Composition of Sulfides of the Au-Te Ore Mineralization in Podgolechnoe and Samolazovskoe Gold-Ore Deposits (Aldan Shield, Russia)

2018 ◽  
Vol 769 ◽  
pp. 227-232
Author(s):  
Nataliya Rusinova ◽  
Vasilii Ivanovich Leontev
Keyword(s):  
Isotopic Composition ◽  
Significant Contribution ◽  
Isotopic Ratio ◽  
Aldan Shield ◽  
Ore Deposits ◽  
Sulfur Isotopic Composition ◽  
Magmatic Source ◽  
Ore Mineralization ◽  
Sulfur Isotopic Ratio ◽  
Ore District

This work presents the results of an analysis of the sulfur isotopic composition of pyrites from different metasomatic rocks of the Samolazovskoe and Podgolechnoe (Central Aldan ore district) deposits. The sulfur isotopic ratio of pyrite from ore-bearing metasomatic rocks of the Podgolechnoe deposit is characterized by δ34S values varying in a range from –1.8 to –5.5 ‰; that of pyrite from the Samolazovskoe deposit is in a range from –6.9 to –12.3‰. This is in agreement with the suggestion that a magmatic source made a significant contribution to the formation of the ore-forming fluid.

On Noble Gas Anomalies in the Great Namaqualand Troilite

1968 ◽  
Vol 23 (9) ◽  
pp. 1266-1271 ◽  
Author(s):  
E. C. Alexander ◽  
J. H. Bennett ◽  
O. K. Manuel
Keyword(s):  
Neutron Activation ◽  
Isotopic Composition ◽  
Neutron Capture ◽  
Noble Gases ◽  
Noble Gas ◽  
Helium Neon

The abundances and isotopic composition of the stable noble gases were measured in a troilite nodule from the Great Namaqualand fine octahedrite. Helium, neon and argon show a significant spallation component. The major anomalies in krypton and xenon are from neutron capture on selenium and tellurium and from the decay of extinct I129. The abundances of tellurium, iodine and uranium in the troilite were determined by neutron activation analyses and compared with the xenon anomalies. The results indicate that part of the excess Xe129 is from neutron capture on tellurium and the remainder is due to the retention of radiogenic Xe129 from the decay of extinct I129, about 200 million years after an initial I129/I127 = 3 × 10-3.

Recycling of mercury from the atmosphere-ocean system into volcanic-arc–associated epithermal gold systems

Geology ◽  
2020 ◽  
Author(s):  
Changzhou Deng ◽  
Guangyi Sun ◽  
Yimeng Rong ◽  
Ruiyang Sun ◽  
Deyou Sun ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Marine Sediments ◽  
Northeast China ◽  
Active Continental Margin ◽  
Volcanic Belt ◽  
Gold Deposits ◽  
Ore Deposits ◽  
Epithermal Gold ◽  
Volcanic Arc ◽  
South China Craton

Photochemical processes generate mass-independent fractionation (MIF) of mercury (Hg) isotopes in the atmosphere-ocean system, and the subduction of marine sediments or hydrated oceanic crust may recycle the resultant Hg isotope signature into the volcanic-arc environment. This environment typically hosts epithermal gold deposits, which are characterized by a specific Hg-Sb-As metal association. We investigated the Hg isotopic composition of seven volcanic-arc–related epithermal gold deposits in northeast China and revisited the isotopic composition of Hg in hydrothermal ore deposits in circum-Pacific and Mediterranean volcanic arcs. The gold ore samples in northeast China mostly display positive Δ199Hg values (0.11‰ ± 0.07‰, 1σ, n = 48) similar to those observed in the Pacific Rim (0.07‰ ± 0.09‰, 1σ, n = 182) and the Mediterranean Cenozoic volcanic belt (0.09‰ ± 0.08‰, 1σ, n = 9). Because Hg in marine sediments and seawater has positive Δ199Hg, we infer that Hg-bearing epithermal deposits in active continental margin settings receive most Hg from recycled seawater in marine sediments, through the release of Hg by dehydration from the subducting oceanic slab. However, negative to near-zero Δ199Hg values were observed in Hg-bearing deposits in the South China craton (–0.09‰ ± 0.05‰, 1σ, n = 105) and in the intraplate magmatic-hydrothermal Almadén Hg deposit in Spain (–0.02‰ ± 0.06‰, 1σ, n = 26), which are considered to relate to basement and mantle sources, respectively. Hg isotopes have the potential to trace lithospheric Hg cycling.

Isotopic composition and geochemical features of ores of Dzhusa pyrite-polymetallic deposit (South Urals)

2019 ◽  
pp. 78-83
Author(s):  
E. I. Yartsev ◽  
I. V. Vikentyev ◽  
N. I. Eremin
Keyword(s):  
Isotopic Composition ◽  
Inductively Coupled Plasma ◽  
Sulfur Isotopes ◽  
Ore Deposits ◽  
South Urals ◽  
Sulfur Isotopic Composition ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Highly Sensitive ◽  
First Time

The sulfur isotopic composition was studied for the main morphological types and generation of sulfides composing the ore of the Dzhusinsky deposit, and the content of trace elements was analyzed using the highly sensitive method of mass spectrometry with inductively coupled plasma and laser sampling (LA-ICP-MS). Both types of studies were performed for ore deposits for the first time. According to the geochemistry of sulfur isotopes, its deep magmatic source was reconstructed, which made a predominant contribution to the ore-forming fluid. Using the modules of the STATISTICA, correlations were calculated and the patterns of distribution of micro impurities in sulfide minerals were revealed.

ADDITIONAL MEASUREMENTS OF THE ISOTOPIC COMPOSITION OF LEAD FROM STRATIFORM DEPOSITS

1967 ◽  
Vol 4 (2) ◽  
pp. 245-269 ◽  
Author(s):  
R. G. Ostic ◽  
R. D. Russell ◽  
R. L. Stanton
Keyword(s):  
Isotopic Composition ◽  
Spatial Variation ◽  
Lead Isotope ◽  
Isotope Ratios ◽  
Ore Deposits ◽  
Simplified Model ◽  
Primary System ◽  
Apparent Correlation ◽  
Isotopic Evolution ◽  
Sufficient Precision

This paper pursues the study of an apparent correlation between lead isotope abundance characteristics and features of the deposits in which the lead is discovered. New and precise analyses have been carried out on 55 galena samples, mostly From Australasian ore deposits classified as stratiform. To help clarify the interpretation, certain vein leads related to those which are stratiform have been included, as has one analysis of volcanic cotunnite.New evidence is offered that all leads began their isotopic evolution in a unique primary system which has very restricted spatial variation in the ratios U/Pb and Th/Pb. Leads from certain stratiform deposits approach more closely in isotopic composition the products of the primary system than do vein leads, many of which involve extensive crustal histories thai further modify the isotope ratios. The analyses presented here have sufficient precision to permit a close examination of the differences in isotope ratios between stratiform leads and the products of a simplified model for the primary system. The differences are significant and important.Novel aspects of the experimental technique are discussed.

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