Rare Earth Element and Trace Element Features of Gold‐bearing Pyrite in the Jinshan Gold Deposit, Jiangxi Province
21
Citation
29
Reference
10
Related Paper
Citation Trend
Abstract:
Abstract: Jinshan gold deposit is located in northeastern Jiangxi, South China, which is related to the ductile shear zone. It has a gold reserve of more than 200 tons, with 80% of gold occurring in pyrite. The σREE of gold‐bearing pyrite is as higher as 171.664 ppm on average, with relatively higher light rare earth elements (LREE; 159.556 ppm) and lower HREE (12.108 ppm). The σLREE/σHREE ratio is 12.612 and (La/Yb) N is 11.765. These indicate that pyrite is rich in LREE. The (La/Sm) N ratio is 3.758 and that of (Gd/Yb) N is 1.695. These are obvious LREE fractionations. The rare earth element (REE) distribution patterns show obvious Eu anomaly with average δEu values of 0.664, and δCe anomalies of 1.044. REE characteristics are similar to those of wall rocks (regional metamorphic rocks), but different from those of the Dexing granodiorite porphyry and Damaoshan biotite granite. These features indicate that the ore‐forming materials in the Jinshan gold deposit derived from the wall rocks, and the ore‐forming fluids derived from metamorphic water. The Co/Ni ratio (average value 0.38) of pyrite suggests that the Jinshan gold deposit formed under a medium–low temperature. It is inferred from the values of high‐field strength elements, LREE, Hf/Sm, Nb/La, and Th/La of the pyrite that the ore‐forming fluids of the Jinshan gold deposit derived from metamorphic water with Cl>F.Keywords:
Rare-earth element
Trace element
The major and trace-element chemistry of two pyrite generations (Py1 and Py2) from the Kandilka epithermal prospect was studied by EDS-scanning electron microscopy and laser ablation ICP-MS techniques. Both generations of pyrite are distinguished by occurrence and chemical properties. Pyrite from the first generation (Py1) is established as trace-element poor, sub- to euhedral (mainly single) crystals up to 200 µm. The later As-bearing pyrite (Py2) forms fine-grained semi-massive aggregates with increased contents of trace-elements. Except for arsenic, Py2 is enriched in gold and antimony. The As content of Py2 increases in an oscillatory manner from core to rim, reflecting changes in As activity and the chemical evolution of ore-bearing fluids. The oscillatory-zoned pyrite is composed of complex rhythmic overgrowths of alternating As-rich and As-poor bands. Positive correlation between As- and Au-content in Py2 is characteristic. According to the current results, the Kandilka prospect could be concerned as a low-sulphidation deposit.
Trace element
Cite
Citations (0)
Abstract Scientific studies that use pyrite trace element signatures to facilitate interpretations of the geological history of hydrothermal gold deposits are becoming more common. Given this rise in popularity in pyrite trace element chemistry studies, a review of trace element incorporation in pyrite from various gold deposit classes is highly timely. We provide a global compilation of over 20 000 chemical data points resulting from over 5520 spot measurements of pyrites from five separate ore deposit classes, each of which is known to have high gold concentrations. The ore deposit classes considered here include orogenic gold deposits, Carlin-type gold deposits, high- and low-sulfidation gold deposits, and Au-bearing porphyry systems, whereas the pyrite minor- and trace elements that we consider include Au, As, Bi, Co, Cu, Ni, Pb, Sb, Se, Te, Tl and Zn. Meta-analyses of these data suggest that, on a global scale, both existing pyrite trace element chemistry discrimination tools and the newly-established principal component analysis (PCA) approach have a relatively low efficacy in correctly predicting the metallogenic setting in which the pyrite formed. At a deposit scale, however, pyrite trace element chemistry continues to be a useful tool for understanding Au mineralizing processes, especially when coupled with additional analytical techniques or lines of geological evidence. Further meta-analysis of the data tentatively suggests the solubility limits for the various trace elements in pyrite mineral structure and reveals that the correlations between temperature and trace element incorporation (i.e. pyrite geothermometry) are complex. The study highlights that pyrite, by virtue of its mineralogy and propensity for element substitutions, remains an important repository of chemical information related to the evolution of hydrothermal gold mineralizing systems. In as much as this repository is now readily accessed utilizing modern analytical techniques (e.g. routine LA-ICP-MS mapping of trace element distributions at ppb concentrations; mapping element distributions at the nanoscale using atom probe tomography), its full value will only be realized through continued study into the kinetics and mechanisms of trace element incorporation into pyrite structure at conditions relevant to ore-forming processes.
Trace element
Cite
Citations (24)
Sichuan Province is one of the most important provinces in China for light rare earth element(LREE) resources,where has been produced a large amount of rare earth concentrate in the past 20 years.Rare earth elements ΣREEs) and other useful elements in rare earth concentrates are very important for resource evaluation and enterprise survival.In this paper,geochemistry of rare earth elements(REEs) and trace elements in samples from the Jia,Yi and Bing REE deposits has been studied.The results show that the content of REEs and trace elements in rare earth concentrate samples are changed in different deposit,enterprise and different mineral dressing process.The lowest level of ΣREEs is from Jia(ΣREEs = 41.96%),the highest level is from Bing(ΣREEs =55.83%).ΣREEs of magnetic concentrate(ΣREEs = 49.96%) is higher than flotation concentrate(ΣREEs =41.57%),and ΣREEs from A Company(ΣREEs =48.35%) is higher than from B Company(ΣREEs = 42.92%).The REE distribution patterns of concentrate sample are inherited from rare earth ores while Tb and Yb are depleted,indicating that the mineral dressing process may lead to loss of these elements.REEs are enriched in concentrate sample,and Mo,Bi,Pb,Ga,Th,U,W are also enriched.Especially,Mo and Ga are in cut-off grade.These results indicate that it is necessary to increase REE grade of rare earth concentrate,and to take appropriate measures to reclaim higher concentration elements.
Rare-earth element
Trace element
Cite
Citations (0)
Pyrite is the most common sulphide in a wide range of ore deposits and well known to host numerous trace elements, with implications for recovery of valuable metals and for generation of clean concentrates. Trace element signatures of pyrite are also widely used to understand ore-forming processes. Pyrite is an important component of the Olympic Dam Cu–U–Au–Ag orebody, South Australia. Using a multivariate statistical approach applied to a large trace element dataset derived from analysis of random pyrite grains, trace element signatures in Olympic Dam pyrite are assessed. Pyrite is characterised by: (i) a Ag–Bi–Pb signature predicting inclusions of tellurides (as PC1); and (ii) highly variable Co–Ni ratios likely representing an oscillatory zonation pattern in pyrite (as PC2). Pyrite is a major host for As, Co and probably also Ni. These three elements do not correlate well at the grain-scale, indicating high variability in zonation patterns. Arsenic is not, however, a good predictor for invisible Au at Olympic Dam. Most pyrites contain only negligible Au, suggesting that invisible gold in pyrite is not commonplace within the deposit. A minority of pyrite grains analysed do, however, contain Au which correlates with Ag, Bi and Te. The results are interpreted to reflect not only primary patterns but also the effects of multi-stage overprinting, including cycles of partial replacement and recrystallisation. The latter may have caused element release from the pyrite lattice and entrapment as mineral inclusions, as widely observed for other ore and gangue minerals within the deposit. Results also show the critical impact on predictive interpretations made from statistical analysis of large datasets containing a large percentage of left-censored values (i.e., those falling below the minimum limits of detection). The treatment of such values in large datasets is critical as the number of these values impacts on the cluster results. Trimming of datasets to eliminate artefacts introduced by left-censored data should be performed with caution lest bias be unintentionally introduced. The practice may, however, reveal meaningful correlations that might be diluted using the complete dataset.
Trace element
Gangue
Overprinting
Cite
Citations (30)