@misc{10481/72948,
year = {2021},
month = {9},
url = {http://hdl.handle.net/10481/72948},
abstract = {Spinel peridotite xenoliths (one plagioclase-
bearing) hosted in alkaline basalts
from Tallante (southeast Spain) record the
mineralogical and geochemical fingerprint
of the subcontinental lithospheric mantle
(SCLM) evolution beneath the southern Iberian
margin. Mantle metasomatism in fertile
lherzolites caused the crystallization of clinopyroxene
+ orthopyroxene + spinel clusters
through the percolation of Miocene subalkaline
melts during the westward migration of
the subduction front in the western Mediterranean.
In the Pliocene, heat and volatiles
provided by alkaline host-magmas triggered
very low melting degrees of metasomatic
pyroxene-spinel assemblages, producing
melt quenched to silicate glass and reactive
spongy coronae around clinopyroxene and
spinel. Refertilization of the Tallante peridotites
induced the precipitation of base-metal
sulfides (BMS) included in metasomatic
clino- and orthopyroxene. These sulfides
consist of pentlandite ± chalcopyrite ± bornite
aggregates with homogeneous composition
in terms of major elements (Ni, Fe, Cu)
and semi-metals (Se, As, Te, Sb, Bi), but with
wide variability of platinum-group elements
(PGE) fractionation (0.14 < PdN/IrN < 30.74).
Heterogeneous PGE signatures, as well
as the presence of euhedral Pt-Pd-Sn-rich
platinum-group minerals (PGM) and/or Auparticles
within BMS, cannot be explained by
conventional models of chalcophile partitioning
from sulfide melt. Alternatively, we suggest
that they reflect the incorporation of distinct
populations of BMS, PGM, and metal
nanoparticles (especially of Pt, Pd, and Au)
during mantle melting and/or melt percolation.
Therefore, we conclude that Miocene
subalkaline melts released by asthenosphere
upwelling upon slab tearing of the Iberian
continental margin effectively stored metals
in metasomatized domains of this sector
of the SCLM. Remarkably high Au concentrations
in Tallante BMS (median 1.78 ppm)
support that these metasomatized domains
provided a fertile source of metals, especially
gold, for the ore-productive Miocene magmatism
of the westernmost Mediterranean.},
organization = {Junta de Andalucia	B-RNM-189-UGR18},
organization = {European Social Fund (ESF)},
organization = {European Commission		
BES-2017-079949	
PID2019-111715GB-I00/AEI/10.13039/501100011033	
RTI2018-099157-A-I00},
publisher = {Geological Society of America},
title = {Metallogenic fingerprint of a metasomatized lithospheric mantle feeding gold endowment in the western Mediterranean basin},
doi = {10.1130/B36065.1},
author = {Schettino, Erwin and Marchesi, Claudio and González Jiménez, José María and Gervilla Linares, Fernando and Garrido Marín, Carlos Jesús},
}