Segovia-More M., Torró L., Villanova-de-Benavent C., Ramirez-Briones J., Baby Patrice, Ruiz A. I., Cuevas J., Vallance J., Monnier L., Laurent O., Salvi S., Proenza J. A., Nieto F. (2026). Mixed primary mica - secondary ion-clay volcanogenic sedimentary lithium deposits in the Neogene Macusani Volcanic Field, Puno, Peru. Mineralium Deposita, [Early access], p. [20 p.]. ISSN 0026-4598.
Titre du document
Mixed primary mica - secondary ion-clay volcanogenic sedimentary lithium deposits in the Neogene Macusani Volcanic Field, Puno, Peru
Année de publication
2026
Auteurs
Segovia-More M., Torró L., Villanova-de-Benavent C., Ramirez-Briones J., Baby Patrice, Ruiz A. I., Cuevas J., Vallance J., Monnier L., Laurent O., Salvi S., Proenza J. A., Nieto F.
Source
Mineralium Deposita, 2026,
[Early access], p. [20 p.] ISSN 0026-4598
The Falchani Lithium Project, a volcanogenic sedimentary deposit in the Neogene Macusani Volcanic Field (Puno, Peru), hosts > 5.5 Mt Li2CO3 resources and represents a significant potential complementary source for South American lithium production, currently dominated by Andean salar deposits of the Lithium Triangle. The ore comprises volcanogenic tuff and breccia subdivided into the Lithium-rich Tuff and stratigraphically overlying and underlying Upper and Lower Breccia units, respectively. Primary minerals include quartz, feldspars, and trioctahedral Li-F micas (zinnwaldite and lepidolite). Secondary minerals define a vertical mineralogical zonation. The Lithium-rich Tuff is characterized by abundant kaolinite and the preservation of Li-F micas, whereas the Upper and Lower Breccia are dominated by dioctahedral smectites (beidellite-montmorillonite series) with scarce, corroded relict micas. Zeolites locally occur as the predominant secondary phase in brecciated Lithium-rich Tuff samples. Lithium contents peak in the Lithium-rich Tuff (3000-4200 ppm Li), with the bulk hosted by Li-F micas, and only 7% as exchangeable Li. Conversely, the Upper and Lower Breccia units contain < 3000 ppm Li predominantly in interlayer positions of smectites, yielding high exchangeable Li proportions (63-88%). This vertical variation reflects restricted fluid flow through the impermeable Lithium-rich Tuff versus pervasive alkaline hydrothermal fluid circulation through brecciated units. Falchani is unusual in having both magmatic and authigenic lithium-rich phases. These observations support a tentative classification of Falchani as a mixed primary mica-secondary ion-clay volcanogenic sedimentary lithium deposit, a mineralization type not previously documented.
Plan de classement
Géologie et formations superficielles [064]
Description Géographique
PEROU ; MACUSANI VOLCAN
Localisation
Fonds IRD [F B010097369]
Identifiant IRD
fdi:010097369
