Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
- Marco E. Ciriotti
- Messaggi: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Prossima pubblicazione.
Referenza:
▪ Herrmann, J., Voegelin, A., Palatinus, L., Mangold, S., Majzlan, J. (2018): Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains. European Journal of Mineralogy, 30, (in press).
Abstract:
Soils at the locality Erzmatt near the village of Buus in the Swiss Jura Mountains are part of the oxidation zone of a small hydrothermal Fe–As–Tl ore occurrence in dolomite rock. The soils are characterized mostly by near-neutral pH values, buffered by the dolomite and limestone bedrock. The concentrations of As and Tl in the soil profiles increase with depth and attain maximum values of ∼20 000 mg/kg for As and ∼10 000 mg/kg for Tl. Using a combination of mineralogical, geochemical, and spectroscopic techniques, we investigated soil samples from the Erzmatt with respect to the characterization of As- and Tl-bearing secondary minerals using total digestions, powder X-ray diffraction, X-ray absorption spectroscopy (XAS), polarized light microscopy, electron microprobe analysis (EMPA), scanning and transmission electron microscopy (SEM, TEM). Arsenic K edge XAS data reveal little variation in bulk soil As speciation and suggest that most As is arsenate bound to iron oxides. Samples with As contents exceeding ∼1 wt% As2O5 contain abundant crystals of bariopharmacosiderite [Ba0.5Fe4(OH)4(AsO4)3·nH2O] in the voids in the soil matrix. Less commonly, Ca–Fe arsenates (arseniosiderite) were identified. An earlier study also identified Tl(I)-containing jarosite and avicennite (Tl2O3) as secondary Tl-bearing minerals. The EMP analyses reveal the degree of jarosite–dorallcharite [(K,Tl)Fe3(SO4)2(OH)6] solid solution formation, and indicate the presence of Tl2O3 with variable contents of As and P. Using electron diffraction, Tl2O3 with low As content was positively identified as avicennite. The platy morphology of the Tl2O3 aggregates is not compatible with the cubic morphology of avicennite, indicating that they may be pseudomorphs after an unknown primary mineral, possibly carlinite, Tl2S. The identification of bariopharmacosiderite, jarosite and avicennite in near-neutral soils points to their stability at near-neutral soil pH (in contrast to scorodite) and indicates their potential for the storage and retention of toxic As and Tl in mine wastes and contaminated environments. The mineralization on the Erzmatt could be an example of a geochemical anomaly similar to the famous Lengenbach deposit (Switzerland) before the metamorphic overprint at Lengenbach.
Referenza:
▪ Herrmann, J., Voegelin, A., Palatinus, L., Mangold, S., Majzlan, J. (2018): Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains. European Journal of Mineralogy, 30, (in press).
Abstract:
Soils at the locality Erzmatt near the village of Buus in the Swiss Jura Mountains are part of the oxidation zone of a small hydrothermal Fe–As–Tl ore occurrence in dolomite rock. The soils are characterized mostly by near-neutral pH values, buffered by the dolomite and limestone bedrock. The concentrations of As and Tl in the soil profiles increase with depth and attain maximum values of ∼20 000 mg/kg for As and ∼10 000 mg/kg for Tl. Using a combination of mineralogical, geochemical, and spectroscopic techniques, we investigated soil samples from the Erzmatt with respect to the characterization of As- and Tl-bearing secondary minerals using total digestions, powder X-ray diffraction, X-ray absorption spectroscopy (XAS), polarized light microscopy, electron microprobe analysis (EMPA), scanning and transmission electron microscopy (SEM, TEM). Arsenic K edge XAS data reveal little variation in bulk soil As speciation and suggest that most As is arsenate bound to iron oxides. Samples with As contents exceeding ∼1 wt% As2O5 contain abundant crystals of bariopharmacosiderite [Ba0.5Fe4(OH)4(AsO4)3·nH2O] in the voids in the soil matrix. Less commonly, Ca–Fe arsenates (arseniosiderite) were identified. An earlier study also identified Tl(I)-containing jarosite and avicennite (Tl2O3) as secondary Tl-bearing minerals. The EMP analyses reveal the degree of jarosite–dorallcharite [(K,Tl)Fe3(SO4)2(OH)6] solid solution formation, and indicate the presence of Tl2O3 with variable contents of As and P. Using electron diffraction, Tl2O3 with low As content was positively identified as avicennite. The platy morphology of the Tl2O3 aggregates is not compatible with the cubic morphology of avicennite, indicating that they may be pseudomorphs after an unknown primary mineral, possibly carlinite, Tl2S. The identification of bariopharmacosiderite, jarosite and avicennite in near-neutral soils points to their stability at near-neutral soil pH (in contrast to scorodite) and indicates their potential for the storage and retention of toxic As and Tl in mine wastes and contaminated environments. The mineralization on the Erzmatt could be an example of a geochemical anomaly similar to the famous Lengenbach deposit (Switzerland) before the metamorphic overprint at Lengenbach.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Marco E. Ciriotti
- Messaggi: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Penso di ben ricordare che una presentazione su questa speciale località è stata presentata da Nicolas Meisser al Susy - Sulfosalts Symposium tenutosi a Tavagnasco l'anno scorso.
Gli autori del precedente messaggio anticipano buona parte di quanto Nicolas Meisser intendeva pubblicare?
Gli autori del precedente messaggio anticipano buona parte di quanto Nicolas Meisser intendeva pubblicare?
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Marco E. Ciriotti
- Messaggi: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Pubblicazione effeattuata.
Referenza:
▪ Herrmann, J., Voegelin, A., Palatinus, L., Mangold, S., Majzlan, J. (2018): Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains. European Journal of Mineralogy, 30, 887-898.
Referenza:
▪ Herrmann, J., Voegelin, A., Palatinus, L., Mangold, S., Majzlan, J. (2018): Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains. European Journal of Mineralogy, 30, 887-898.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Carlo Alciati
- Messaggi: 1502
- Iscritto il: lun 30 ago, 2004 16:47
- Località: Ivrea (TO)
- Contatta:
Re: Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Marco, si può avere una copia dell'articolo?
Era infatti una delle presentazioni di SuSy2017.
Era infatti una delle presentazioni di SuSy2017.
Carlo Alciati
Segretario GMI - Gruppo Mineralogico di Ivrea "Aldo Nicola"
Segretario GMI - Gruppo Mineralogico di Ivrea "Aldo Nicola"
- Marco E. Ciriotti
- Messaggi: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Appena pubblicato sulle pagine dell'editore (al momento le informazioni sono state avute da uno degli autori) te lo passo.Marco, si può avere una copia dell'articolo?
Era infatti una delle presentazioni di SuSy2017.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Marco E. Ciriotti
- Messaggi: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Spedito a Carlo.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
-
- Messaggi: 200
- Iscritto il: mar 13 giu, 2006 23:32
- Località: varese
Re: Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Sono interessato a una copia dell'articolo.
Grazie. Vanini
Grazie. Vanini
vaninu
-
- Messaggi: 310
- Iscritto il: lun 02 gen, 2017 17:34
- Località: lugano
- Contatta:
Re: Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Scusate la mia ignoranza: ma che differenza c'è con la fetiasite???
Ma non ho ancora visitato mindat!
Ma non ho ancora visitato mindat!
- Marco E. Ciriotti
- Messaggi: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Spedito anche a Franco.Sono interessato a una copia dell'articolo.
Grazie. Vanini
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Carlo Alciati
- Messaggi: 1502
- Iscritto il: lun 30 ago, 2004 16:47
- Località: Ivrea (TO)
- Contatta:
Re: Secondary Fe–As–Tl mineralization in soils near Buus in the Swiss Jura Mountains
Grazie Marco.
Carlo Alciati
Segretario GMI - Gruppo Mineralogico di Ivrea "Aldo Nicola"
Segretario GMI - Gruppo Mineralogico di Ivrea "Aldo Nicola"
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