Details
| Original language | English |
|---|---|
| Pages (from-to) | 1-20 |
| Number of pages | 20 |
| Journal | Chemical geology |
| Volume | 488 |
| Publication status | Published - 5 Jun 2018 |
Abstract
Tetrahedrite [(Cu,Fe,Zn) 12(Sb,As) 4S 13] is commonly present in many ore deposits and may be transferred to mining waste. Here, we describe the behavior of all elements in tetrahedrite during oxidative dissolution in a natural oxidation zone at Piesky (Slovakia), this being a long-term analogue of weathering of tetrahedrite-rich mining wastes. Electron microprobe work identified initial, early, advanced, and mature stages of weathering. The initial stages include formation of secondary covellite and chalcocite, the following stages only oxidic products, divided into greenish masses and brown veinlets. Both of them are nanocrystalline mixtures of minerals. The masses are Cu-Sb-As-rich and consist of a nanocrystalline pyrochlore phase. The veinlets are Fe-Sb-As rich and contain tripuhyite, goethite, and pyrochlores. Quantitative elemental budgets show that some elements (Zn, S, Ni, Co) are rapidly lost whereas others (especially Cu and As) are retained and form copper arsenates in the mature stages of weathering. About 10% As and almost 50% of Sb are lost during weathering, likely released into water; some Sb is stored in secondary minerals such as camérolaite, cualstibite, or tripuhyite. Light carbon isotopic composition (δ 13C down to −11.1‰) document significant biological contribution for C in the secondary minerals. Copper isotopes become progressively heavier during weathering (from initial δ 65Cu of −2.45‰ in tetrahedrite up to 4.3‰ in some azurite samples but −6.3‰ in covellite and chalcocite), documenting cyclic removal of light copper isotopes into covellite and chalcocite. The observation of elemental synergies during weathering of tetrahedrite shows that the solubility and mobility of As is controlled by copper arsenates, not by iron oxides, in an environment rich in tetrahedrite but poor in pyrite. Antimony, another element of environmental concern, is mostly released into water and creates low-concentration anomalies in stream sediments and soils.
Keywords
- Carbon, oxygen, copper isotopes, Electron microprobe, Radiometric dating, Stibiconite, Tetrahedrite, Tripuhyite, Water geochemistry, Weathering
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
- Earth and Planetary Sciences(all)
- Geology
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In: Chemical geology, Vol. 488, 05.06.2018, p. 1-20.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Synergies in elemental mobility during weathering of tetrahedrite [(Cu,Fe,Zn)12(Sb,As)4S13]: Field observations, electron microscopy, isotopes of Cu, C, O, radiometric dating, and water geochemistry
AU - Majzlan, J.
AU - Kiefer, S.
AU - Hermann, Julia
AU - Števko, M.
AU - Sejkora, J.
AU - Chovan, M.
AU - Lánczos, T.
AU - Lazarov, M.
AU - Gerdes, A.
AU - Langenhorst, F.
AU - Borčinová Radková, A.
AU - Jamieson, H.
AU - Milovský, R.
N1 - Publisher Copyright: © 2018 Elsevier B.V.
PY - 2018/6/5
Y1 - 2018/6/5
N2 - Tetrahedrite [(Cu,Fe,Zn) 12(Sb,As) 4S 13] is commonly present in many ore deposits and may be transferred to mining waste. Here, we describe the behavior of all elements in tetrahedrite during oxidative dissolution in a natural oxidation zone at Piesky (Slovakia), this being a long-term analogue of weathering of tetrahedrite-rich mining wastes. Electron microprobe work identified initial, early, advanced, and mature stages of weathering. The initial stages include formation of secondary covellite and chalcocite, the following stages only oxidic products, divided into greenish masses and brown veinlets. Both of them are nanocrystalline mixtures of minerals. The masses are Cu-Sb-As-rich and consist of a nanocrystalline pyrochlore phase. The veinlets are Fe-Sb-As rich and contain tripuhyite, goethite, and pyrochlores. Quantitative elemental budgets show that some elements (Zn, S, Ni, Co) are rapidly lost whereas others (especially Cu and As) are retained and form copper arsenates in the mature stages of weathering. About 10% As and almost 50% of Sb are lost during weathering, likely released into water; some Sb is stored in secondary minerals such as camérolaite, cualstibite, or tripuhyite. Light carbon isotopic composition (δ 13C down to −11.1‰) document significant biological contribution for C in the secondary minerals. Copper isotopes become progressively heavier during weathering (from initial δ 65Cu of −2.45‰ in tetrahedrite up to 4.3‰ in some azurite samples but −6.3‰ in covellite and chalcocite), documenting cyclic removal of light copper isotopes into covellite and chalcocite. The observation of elemental synergies during weathering of tetrahedrite shows that the solubility and mobility of As is controlled by copper arsenates, not by iron oxides, in an environment rich in tetrahedrite but poor in pyrite. Antimony, another element of environmental concern, is mostly released into water and creates low-concentration anomalies in stream sediments and soils.
AB - Tetrahedrite [(Cu,Fe,Zn) 12(Sb,As) 4S 13] is commonly present in many ore deposits and may be transferred to mining waste. Here, we describe the behavior of all elements in tetrahedrite during oxidative dissolution in a natural oxidation zone at Piesky (Slovakia), this being a long-term analogue of weathering of tetrahedrite-rich mining wastes. Electron microprobe work identified initial, early, advanced, and mature stages of weathering. The initial stages include formation of secondary covellite and chalcocite, the following stages only oxidic products, divided into greenish masses and brown veinlets. Both of them are nanocrystalline mixtures of minerals. The masses are Cu-Sb-As-rich and consist of a nanocrystalline pyrochlore phase. The veinlets are Fe-Sb-As rich and contain tripuhyite, goethite, and pyrochlores. Quantitative elemental budgets show that some elements (Zn, S, Ni, Co) are rapidly lost whereas others (especially Cu and As) are retained and form copper arsenates in the mature stages of weathering. About 10% As and almost 50% of Sb are lost during weathering, likely released into water; some Sb is stored in secondary minerals such as camérolaite, cualstibite, or tripuhyite. Light carbon isotopic composition (δ 13C down to −11.1‰) document significant biological contribution for C in the secondary minerals. Copper isotopes become progressively heavier during weathering (from initial δ 65Cu of −2.45‰ in tetrahedrite up to 4.3‰ in some azurite samples but −6.3‰ in covellite and chalcocite), documenting cyclic removal of light copper isotopes into covellite and chalcocite. The observation of elemental synergies during weathering of tetrahedrite shows that the solubility and mobility of As is controlled by copper arsenates, not by iron oxides, in an environment rich in tetrahedrite but poor in pyrite. Antimony, another element of environmental concern, is mostly released into water and creates low-concentration anomalies in stream sediments and soils.
KW - Carbon, oxygen, copper isotopes
KW - Electron microprobe
KW - Radiometric dating
KW - Stibiconite
KW - Tetrahedrite
KW - Tripuhyite
KW - Water geochemistry
KW - Weathering
UR - http://www.scopus.com/inward/record.url?scp=85046164045&partnerID=8YFLogxK
U2 - 10.1016/j.chemgeo.2018.04.021
DO - 10.1016/j.chemgeo.2018.04.021
M3 - Article
VL - 488
SP - 1
EP - 20
JO - Chemical geology
JF - Chemical geology
SN - 0009-2541
ER -