scholarly journals Trace Element Contents in Sphalerite from the Nayongzhi Zn-Pb Deposit, Northwestern Guizhou, China: Insights into Incorporation Mechanisms, Metallogenic Temperature and Ore Genesis

Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 490 ◽  
Author(s):  
Chen Wei ◽  
Zhilong Huang ◽  
Zaifei Yan ◽  
Yusi Hu ◽  
Lin Ye

The Nayongzhi Zn-Pb deposit, located in the southeastern margin of the Sichuan-Yunnan-Guizhou (S-Y-G) Zn-Pb metallogenic province, China, has been recently discovered in this region and has an estimated resource of 1.52 Mt of metal at average grades of 4.82 wt % Zn and 0.57 wt % Pb. The ore bodies are hosted in the Lower Cambrian Qingxudong Formation dolostone and occur as stratiform, stratoid and steeply dipping veins. The predominant minerals are sphalerite, galena, dolomite, calcite with minor pyrite, and barite. In this paper, the inductively coupled plasma mass spectrometry (ICP-MS) technique has been used to investigate the concentrations of Fe, Cd, Ge, Ga, Cu, Pb, Ag, In, Sn, Sb, Co and Mn in bulk grain sphalerite from the Nayongzhi deposit, in an effort to provide significant insights into the element substitution mechanisms, ore-forming temperature and genesis of the deposit. This study shows that those trace elements (i.e., Cd, In, Sn, Sb, Fe, Mn, Cu, Ga, Ge, Ag, and Co) are present in the form of isomorphism in sphalerite, and strong binary correlation among some elements suggests direct substitution as Zn2+↔Fe2+ and coupled substitutions as Zn2+↔Ga3+ + (Cu, Ag)+ and Zn2+↔In3+ + Sn3+ + □ (vacancy), despite there being no clear evidence for the presence of Sn3+. Sphalerite from the Nayongzhi deposit is enriched in Cd, Ge and Ga and depleted in Fe, Mn, In and Co, which is similar to that of the Mississippi Valley-type (MVT) deposit and significantly different from that of the Volcanogenic Massive Sulfide (VMS) deposit, Sedimentary-exhalative (Sedex) deposit, skarn, and epithermal hydrothermal deposit. Moreover, the ore-forming temperature is relatively low, ranging from 100.5 to 164.4 °C, as calculated by the GGIMFis geothermometer. Geological characteristics, mineralogy and trace element contents of sphalerite suggest that the Nayongzhi deposit is a MVT deposit. In addition, according to the geological characteristics, Ag content in sphalerite, and Pb isotope evidence, the Nayongzhi deposit is distinct from the deposits associated with the Indosinian Orogeny in S-Y-G Zn-Pb metallogenic province (e.g., Huize, Daliangzi, Tianbaoshan and Tianqiao deposits), thus, suggesting that multi-stage Zn-Pb mineralization may have occurred in this region.

2019 ◽  
Vol 156 (9) ◽  
pp. 1565-1586 ◽  
Author(s):  
Chaohui Liu ◽  
Guochun Zhao ◽  
Fulai Liu ◽  
Jia Cai

AbstractThe Bengbu area in the southeastern North China Craton (NCC) consists predominantly of Archean–Palaeoproterozoic (gneissic) granitoids with minor supracrustal rocks (the Fengyang and Wuhe groups). This study presents new zircon laser ablation – inductively coupled plasma – mass spectrometry U–Pb and Lu–Hf isotopic data and trace-element contents for these granitoids, which improve understanding the Archean–Palaeoproterozoic crustal evolution of the NCC. Magmatic zircon U–Pb data reveal that zircons in the (gneissic) granitoids were generated by multi-stage events at 2.93, 2.73, 2.53–2.52 and 2.18–2.13 Ga. Metamorphic zircon U–Pb data obtained from these rocks show two distinct metamorphic ages of 2.49–2.52 and 1.84 Ga, suggesting that the Bengbu area experienced a regional metamorphic event at the end of the Neoarchean Era and encountered reworking by a tectonothermal event associated with the formation of the Palaeoproterozoic Jiao-Liao-Ji Belt. Trace-element compositions of magmatic zircons reveal the highest Ti concentrations (8.08±3.38 ppm) and growth temperatures (718±44 °C) for the zircons aged 2.13–2.17 Ga and an increase in zircon U/Yb ratios from 2.93 Ga (0.34±0.12) through 2.73 Ga (0.96±0.42) to 2.53 Ga (1.05±0.46), but an evident decrease at 2.17–2.13 Ga (0.61±0.40 ppm). Similar Palaeoarchean xenocrystic and detrital zircons with negativeɛHf(t) values, late Mesoarchean magmatic zircons with juvenile Hf isotopic features, early Neoarchean magmatic zircons with model ages of 2.9–3.0 Ga, and two regional metamorphic events at 2.52–2.48 and 1.88–1.80 Ga in the Bengbu and Jiaobei areas indicate a Palaeoarchean–Mesoarchean micro-continent entrained in the Jiao-Liao-Ji Belt at the southeastern NCC.


Author(s):  
Ümit Şengül ◽  
Rıdvan İlgün

There are hundreds of years old wild sweet chestnut trees grown among alder, hornbeam, and pine etc. trees in natural forest of Giresun/TURKEY. In this study, trace element contents of chestnuts collected from chestnut trees in these natural forests were investigated. For this purpose, A total of eight elements, manganese (Mn), iron (Fe), zinc (Zn), nickel (Ni), cobalt (Co), selenium (Se) and lead (Pb) were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) in chestnut samples collected from ten chestnut trees. The content of trace elements was determined separately in fruit, bark and pellicle parts of chestnut. In chestnut fruit samples, highest concentration values in mg kg-1 of Mn, Fe, Zn, Ni, Cu, Se, Co and Pb are: 88.29, 72.96, 27.76 8.25, 7.81, 2.28, 0.056 and 0.043 respectively. Chestnut bark has been shown the highest values as Mn 176.01, Fe 96.55, Zn 26.97, Ni 4.33, Cu 8.91, Se 3.08, Co 0.089 and Pb 0.058 mg kg-1. The highest concentrations of trace elements in chestnut pellicle are found as Mn 176.26, Fe 92.98, Zn 60.06, Ni 5.79, Cu 11.4, Se 3.29, Co 0.135 and Pb 0.095 mg kg-1. These results suggest that natural chestnuts grown in the Giresun region are quite rich nutrients in terms of trace element contents.


2018 ◽  
Vol 1 (1) ◽  
pp. 1-13

Background: Thyroid cancer is an internationally important health problem. The aim of this exploratory study was to evaluate whether significant changes in the thyroid tissue levels of Ag, Co, Cr, Fe, Hg, Rb, Sb, Sc, Se, and Zn exist in the malignantly transformed thyroid. Methods: Thyroid tissue levels of ten trace elements were prospectively evaluated in 41 patients with thyroid malignant tumors and 105 healthy inhabitants. Measurements were performed using non-destructive instrumental neutron activation analysis with high resolution spectrometry of long-lived radionuclides. Tissue samples were divided into two portions. One was used for morphological study while the other was intended for trace element analysis. Results: It was found that contents of Ag, Co, Cr, Hg, and Rb were significantly higher (approximately 12.8, 1.4, 1.6, 19.6, and 1.7 times, respectively) in cancerous tissues than in normal tissues. Conclusions: There are considerable changes in trace element contents in the malignantly transformed tissue of thyroid.


Urolithiasis ◽  
1989 ◽  
pp. 229-231
Author(s):  
J. Hofbauer ◽  
I. Steffan ◽  
H. Schwetz ◽  
G. Vujicic ◽  
O. Zechner

2016 ◽  
Vol 39 (5) ◽  
pp. 1159-1177 ◽  
Author(s):  
R. Jiménez-Ballesta ◽  
F. J. García-Navarro ◽  
S. Bravo ◽  
J. A. Amorós ◽  
C. Pérez-de-los-Reyes ◽  
...  

2011 ◽  
Vol 184 (7) ◽  
pp. 4517-4538 ◽  
Author(s):  
Uwe Buczko ◽  
Rolf O. Kuchenbuch ◽  
Walter Übelhör ◽  
Ludwig Nätscher

1997 ◽  
Vol 61 (405) ◽  
pp. 257-269 ◽  
Author(s):  
Suzanne Y. O'Reilly ◽  
D. Chen ◽  
W. L. Griffin ◽  
C. G. Ryan

AbstractThe proton microprobe has been used to determine contents of Ca, Ti, Ni, Mn and Zn in the olivine of 54 spinel lherzolite xenoliths from Australian and Chinese basalts. These data are compared with proton-probe data for Ni, Mn and Zn in the olivine of 180 garnet peridotite xenoliths from African and Siberian kimberlites. Fe, Mn, Ni and Zn contents are well-correlated; because the spinel lherzolite olivines have higher mean Fe contents than garnet peridotite olivines (average Fo89.6vs. Fo90–92) they also have lower Ni and higher Mn contents. Zn and Fe are well-correlated in garnet peridotite olivine, but in spinel peridotites this relationship is perturbed by partitioning of Zn into spinel. None of these elements shows significant correlation with temperature. Consistent differences in trace-element contents of olivines in the two suites is interpreted as reflecting the greater degree of depletion of Archean garnet peridotites as compared to Phanerozoic spinel lherzolites. Ca and Ti contents of spinel-peridotite olivine are well correlated with one another, and with temperature as determined by several types of geothermometer. However, Ca contents are poorly correlated with pressure as determined by the Ca-in-olivine barometer of Köhler and Brey (1990). This reflects the strong T-dependence of this barometer: the uncertainty in pressure (calculated by this method) which is produced by the ±50°C uncertainty expected of any geothermometer is ca ± 8 kbar, corresponding to the entire width of the spinel-lherzolite field at 900–1200°C.


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