HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Incipient wolframite deposition at Panasqueira (Portugal): W-rutile and tourmaline compositions as proxies for early fluid composition

Abstract : The main event responsible for the deposition of tungsten at Panasqueira was closely associated with strong tourmalinization of the wall rocks. Tourmaline is coeval with a W-rich rutile (up to 8-10 18 wt% W) and both minerals record an early introduction of W in the system, just before the main W deposition. Uranium-Pb dating of the rutile by LA-ICP-MS yielded an age of 305.2±5.7 Ma, which is 6-10 Ma older than the K-Ar age of 296.3±1.2 Ma obtained on muscovite, which was therefore not coeval of wolframite. Major and trace element concentration variations in tourmaline record fluid mixing between two end-members, both considered to be of metamorphic derivation on the basis of REE profiles. We report evidence for a fluid enriched in Co, Cu, Pb, Sc, Sr, V, Cr, Nb, Ta, Sn, interpreted to be of "local" origin, e.g., well-equilibrated with the host formations, and a fluid rich in Li, F, Fe, Mn, W inferred to be of deep origin and related to biotite dehydration. The second fluid carried the metals (in particular Fe and Mn) necessary for wolframite deposition, which were not necessarily inherited from the wall rocks through fluid-rock interaction. Micrometer scale variations in tourmaline and rutile crystal-chemistry are indicative of pulsatory fluid input during tourmalinization.
Document type :
Journal articles
Complete list of metadata

Cited literature [63 references]  Display  Hide  Download

Contributor : Isabelle Dubigeon Connect in order to contact the contributor
Submitted on : Wednesday, October 14, 2020 - 4:42:36 PM
Last modification on : Wednesday, May 11, 2022 - 4:08:07 AM


Files produced by the author(s)



Eleonora Carocci, Christian Marignac, Michel Cathelineau, Laurent Truche, Marc Poujol, et al.. Incipient wolframite deposition at Panasqueira (Portugal): W-rutile and tourmaline compositions as proxies for early fluid composition. Economic Geology, Society of Economic Geologists, 2021, 16 (1), pp.123-146. ⟨10.5382/econgeo.4783⟩. ⟨insu-02965235⟩



Record views


Files downloads