Tourmaline associated with orogenic gold occurrences in the
Silet terrane, South Algeria: Evolution of composition and
redox state during hydrothermal crystallization

J 2025

Tourmaline associated with orogenic gold occurrences in the Silet terrane, South Algeria: Evolution of composition and redox state during hydrothermal crystallization

CHAOUCHE, Ismahen; Jan CEMPÍREK; Mohamed TALBI; Riad Ben El KHAZNADJI; Nadjet Ait TALEB et. al.

Základní údaje

Originální název

Tourmaline associated with orogenic gold occurrences in the Silet terrane, South Algeria: Evolution of composition and redox state during hydrothermal crystallization

Autoři

CHAOUCHE, Ismahen; Jan CEMPÍREK; Mohamed TALBI; Riad Ben El KHAZNADJI; Nadjet Ait TALEB a Yves FUCHS

Vydání

Geochemistry, Elsevier GmbH, 2025, 0009-2819

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10505 Geology

Stát vydavatele

Německo

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 2.900 v roce 2024

Organizační jednotka

Přírodovědecká fakulta

DOI

https://doi.org/10.1016/j.chemer.2025.126259

UT WoS

001540424400001

EID Scopus

2-s2.0-85219010238

Klíčová slova anglicky

Tourmaline; Silet terrane; Gold; Fe3+content; Weathering processes

Štítky

14315010, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 2. 9. 2025 15:39, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

In the Silet terrane (western Hoggar, southern Algeria), gold occurs in association with tourmaline in quartz veins. In the Assouf Mellen, Seldrar, and Idreksi occurrences, gold-bearing veins cut diorite and granodiorite complexes of the pre-orogenic Tonalite-Trondhjemite-Granodiorite group (868-840 Ma). These veins trend dominantly in the N-S, NE-SW, and NW-SE directions, and are preferentially developed at the intersection zones of secondary NE-SW and NW-SE fault splays off the main 4 degrees 30 ' fault zone (Iskel Shear Zone). Free gold is present as inclusions disseminated in quartz and tourmaline, and as fissure-fillings in deformed tourmaline crystals. Gold was also found as inclusions in chalcopyrite and in iron oxides. Based on the mineral chemistry, the tourmaline belongs to the alkali group and represents the schorl-dravite and foitite-oxy-foitite series and shows evolution trends to bosiite/povondraite; tourmaline components from the calcic group (lucchesiite, magnesio-lucchesiite) are minor only. Tourmaline in Silet was likely formed as Aldeficient Fe3+-enriched schorl (Tur I), later recrystallized (Tur II) and enriched in Mg and Al with higher Xsite vacancy (Mg-rich schorl to Fe-rich dravite). In the Seldrar occurrences (middle part of Silet terrane), gold is associated with tourmaline with high initial Fe3+-contents (Tur I) while the assemblage of the later Tur II is barren. The evolution towards Fe3+-rich schorl may be explained as a result of more oxidizing conditions in the late stage of formation of the mineralized quartz veins. Part of gold was remobilized by low-temperature weathering processes.

Citovat

CHAOUCHE, Ismahen; Jan CEMPÍREK; Mohamed TALBI; Riad Ben El KHAZNADJI; Nadjet Ait TALEB a Yves FUCHS. Tourmaline associated with orogenic gold occurrences in the Silet terrane, South Algeria: Evolution of composition and redox state during hydrothermal crystallization. Geochemistry. Elsevier GmbH, 2025, roč. 85, č. 2, s. 126259-126275. ISSN 0009-2819. Dostupné z: https://doi.org/10.1016/j.chemer.2025.126259.

@article{2515395,
   author = {Chaouche, Ismahen and Cempírek, Jan and Talbi, Mohamed and Khaznadji, Riad Ben El and Taleb, Nadjet Ait and Fuchs, Yves},
   article_number = {2},
   doi = {https://doi.org/10.1016/j.chemer.2025.126259},
   keywords = {Tourmaline; Silet terrane; Gold; Fe3+content; Weathering processes},
   language = {eng},
   issn = {0009-2819},
   journal = {Geochemistry},
   title = {Tourmaline associated with orogenic gold occurrences in the Silet terrane, South Algeria: Evolution of composition and redox state during hydrothermal crystallization},
   url = {https://www.sciencedirect.com/science/article/pii/S0009281925000145},
   volume = {85},
   year = {2025}
}

TY  - JOUR
ID  - 2515395
AU  - Chaouche, Ismahen - Cempírek, Jan - Talbi, Mohamed - Khaznadji, Riad Ben El - Taleb, Nadjet Ait - Fuchs, Yves
PY  - 2025
TI  - Tourmaline associated with orogenic gold occurrences in the Silet terrane, South Algeria: Evolution of composition and redox state during hydrothermal crystallization
JF  - Geochemistry
VL  - 85
IS  - 2
SP  - 126259
EP  - 126259
PB  - Elsevier GmbH
SN  - 00092819
KW  - Tourmaline
KW  - Silet terrane
KW  - Gold
KW  - Fe3+content
KW  - Weathering processes
UR  - https://www.sciencedirect.com/science/article/pii/S0009281925000145
N2  - In the Silet terrane (western Hoggar, southern Algeria), gold occurs in association with tourmaline in quartz veins. In the Assouf Mellen, Seldrar, and Idreksi occurrences, gold-bearing veins cut diorite and granodiorite complexes of the pre-orogenic Tonalite-Trondhjemite-Granodiorite group (868-840 Ma). These veins trend dominantly in the N-S, NE-SW, and NW-SE directions, and are preferentially developed at the intersection zones of secondary NE-SW and NW-SE fault splays off the main 4 degrees 30 ' fault zone (Iskel Shear Zone). Free gold is present as inclusions disseminated in quartz and tourmaline, and as fissure-fillings in deformed tourmaline crystals. Gold was also found as inclusions in chalcopyrite and in iron oxides. Based on the mineral chemistry, the tourmaline belongs to the alkali group and represents the schorl-dravite and foitite-oxy-foitite series and shows evolution trends to bosiite/povondraite; tourmaline components from the calcic group (lucchesiite, magnesio-lucchesiite) are minor only. Tourmaline in Silet was likely formed as Aldeficient Fe3+-enriched schorl (Tur I), later recrystallized (Tur II) and enriched in Mg and Al with higher Xsite vacancy (Mg-rich schorl to Fe-rich dravite). In the Seldrar occurrences (middle part of Silet terrane), gold is associated with tourmaline with high initial Fe3+-contents (Tur I) while the assemblage of the later Tur II is barren. The evolution towards Fe3+-rich schorl may be explained as a result of more oxidizing conditions in the late stage of formation of the mineralized quartz veins. Part of gold was remobilized by low-temperature weathering processes.
ER  -

CHAOUCHE, Ismahen; Jan CEMPÍREK; Mohamed TALBI; Riad Ben El KHAZNADJI; Nadjet Ait TALEB a Yves FUCHS. Tourmaline associated with orogenic gold occurrences in the Silet terrane, South Algeria: Evolution of composition and redox state during hydrothermal crystallization. \textit{Geochemistry}. Elsevier GmbH, 2025, roč.~85, č.~2, s.~126259-126275. ISSN~0009-2819. Dostupné z: https://doi.org/10.1016/j.chemer.2025.126259.

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