Τίτλος:
REE-enriched skarns in collisional settings: The example of Xanthi's Fe-skarn, Rhodope Metallogenetic Massif, Northern Greece
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
The garnet-epidote zone in the Xanthi Fe-skarn at the Rhodope Metallogenetic Massif, northern Greece, includes noteworthy cerium mineralization manifested by the presence of epidote-(Ce) containing up to ~130,000 ppm ΣREE and ~ 87,000 ppm Ce. The REE skarn represents a late evolutionary phase of the Xanthi's Fe-skarn in a collisional setting.- The epidote-(Ce) was deposited under pressures of ~1000 bars, at temperatures of ~345° to ~400 °C, from an almost pH neutral, saline, Ce-bearing, heterogeneous trapped, skarn-forming fluids with elevated log[αREE3+/(αH+)3] values. Thermodynamic two-stage modeling suggests that Ca metasomatism (e.g., decrease of the logαCa2+(aq) values) coupled with Ce fractionation (e.g., increase of the logαCe(CO3)+(aq) values) of the skarn-forming fluids led to the formation of epidote-(Ce). The major mechanism for the Ce-enrichment in the metasomatic fluids was the remobilization of the REE from the I-type granodiorite of Xanthi, in a back-arc setting due to subduction retreat. © 2020 Elsevier B.V.
Συγγραφείς:
Fitros, M.
Tombros, S.F.
Kokkalas, S.
Kilias, S.P.
Perraki, M.
Skliros, V.
Simos, X.C.
Papaspyropoulos, K.
Avgouropoulos, G.
Williams-Jones, A.E.
Zhai, D.
Hatzipanagiotou, K.
Περιοδικό:
LITHOS - AMSTERDAM
Λέξεις-κλειδιά:
cerium; collision zone; enrichment; epidote; iron; metallogenesis; metasomatism; mineralization; rare earth element; remobilization; skarn; thermodynamics, Greece
DOI:
10.1016/j.lithos.2020.105638
