Polymetallic interactions of Zn-Pb-Cu in blue/green-colored speleothems from Malaval Cave (France)
Abstract
Speleothems rarely exhibit stunning colors such as red, yellow, green, or blue. The colorations are often linked to elevated heavy metal ion concentration in the drip water and thus to a metal source/pollution in the catchment area. Here the blue-green speleothems coloration in Malaval Cave (Lozère, France) is characterized by a wide panel of optical, mineralogical and geochemical techniques. These techniques were applied on several small blue or white stalactites and a larger greenish stalactite. The speleothems are mostly composed of aragonite and contain variable amounts of Zn, Cu and Pb, which cause the colorations. Zn and Cu are mostly present in substitution in the aragonite and Cu2+ is the main cause of the blue coloration. Zn is also found in small amorphous gel particles, containing minor amounts of Mg, Cu and Si. These phases are responsible for microscopical scale variations in the blue coloration. Pb is present as Pb2+ ions in substitution within the aragonite, creating a saturated blue-to-greenish coloration. This coloration may depend on the Pb/Zn ratio due to metallic interaction. Pb, Zn and Cu ratios indicate that Pb likely deposited from distinct fluids and at a different timing than Cu and Zn. All three metals likely originate from the leaching of Pbsingle bondZn ores in the Jurassic formations surrounding the cave.
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BibTeX
@article{vlieghe2026polymetallic,
title = {{Polymetallic interactions of Zn-Pb-Cu in blue/green-colored speleothems from Malaval Cave (France)}},
author = {Martin Vlieghe and Gaëtan Rochez and Stéphane Pire-Stevenne and Alexandre Felten and Marie Dechamps and Sébastien Mouchet and Francesca Cecchet and Olivier Bruguier and Jean-Louis Galéra and Gipsi Lima-Mendez and Marc Llirós Dupré and Johan Yans},
journal = {Chemie der Erde / Geochemistry},
year = {2026},
month = sep,
doi = {10.1016/j.chemer.2025.126285},
url = {https://hal.science/hal-05736011v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Polymetallic interactions of Zn-Pb-Cu in blue/green-colored speleothems from Malaval Cave (France)
AU - Martin Vlieghe
AU - Gaëtan Rochez
AU - Stéphane Pire-Stevenne
AU - Alexandre Felten
AU - Marie Dechamps
AU - Sébastien Mouchet
AU - Francesca Cecchet
AU - Olivier Bruguier
AU - Jean-Louis Galéra
AU - Gipsi Lima-Mendez
AU - Marc Llirós Dupré
AU - Johan Yans
PY - 2026
DA - 2026/09/02
JO - Chemie der Erde / Geochemistry
DO - 10.1016/j.chemer.2025.126285
UR - https://hal.science/hal-05736011v1
AB - Speleothems rarely exhibit stunning colors such as red, yellow, green, or blue. The colorations are often linked to elevated heavy metal ion concentration in the drip water and thus to a metal source/pollution in the catchment area. Here the blue-green speleothems coloration in Malaval Cave (Lozère, France) is characterized by a wide panel of optical, mineralogical and geochemical techniques. These techniques were applied on several small blue or white stalactites and a larger greenish stalactite. The speleothems are mostly composed of aragonite and contain variable amounts of Zn, Cu and Pb, which cause the colorations. Zn and Cu are mostly present in substitution in the aragonite and Cu2+ is the main cause of the blue coloration. Zn is also found in small amorphous gel particles, containing minor amounts of Mg, Cu and Si. These phases are responsible for microscopical scale variations in the blue coloration. Pb is present as Pb2+ ions in substitution within the aragonite, creating a saturated blue-to-greenish coloration. This coloration may depend on the Pb/Zn ratio due to metallic interaction. Pb, Zn and Cu ratios indicate that Pb likely deposited from distinct fluids and at a different timing than Cu and Zn. All three metals likely originate from the leaching of Pbsingle bondZn ores in the Jurassic formations surrounding the cave.
SN - 0009-2819
ER -