RT Journal Article
T1 Micron-to-nanoscale investigation of Cu-Fe-Ni sulfide inclusions within laurite (Ru, Os)S2 from chromitites
A1 González Jiménez, José María
A1 González Pérez, Igor
A1 Plissart, Gaëlle
A1 Ferreira García, Amira Rosa
A1 Schettino, Erwin
A1 Yesares Ortiz, María Dolores
A1 Schilling, Manuel E.
A1 Corgne, Alexandre
A1 Gervilla, Fernando
AB This paper provides a top-down nanoscale analysis of Cu-Ni-Fe sulfide inclusions in laurite from the Taitao ophiolite (Chile) and the Kevitsa mafic-ultramafic igneous intrusion (Finland). High-resolution transmission electron microscopy (HRTEM) reveal that Cu-Ni-Fe sulfide inclusions are euhedral to (sub)-anhedral (i.e., droplet-like) and form single, biphasic or polyphasic grains, made up of different polymorphs, polytypes and polysomes even within a single sulfide crystal. Tetragonal (I4 d) and cubic (F 3m) chalcopyrite (CuFeS2) host frequent fringes of bornite (Cu5FeS4; cubic F3m and/or orthorhombic Pbca) ± talnakhite (Cu9(Fe, Ni)8S16; cubic I3m) ± pyrrhotite (Fe1 − xS; monoclinic C2/c polytype 4C and orthorhombic Cmca polytype 11C) ± pentlandite ((Ni, Fe)9S8; cubic Fm3m). Pentlandite hosts fringes of pyrrhotite, bornite and/or talnakhite. Laurite and Cu-Fe-Ni sulfide inclusions display coherent, semi-coherent and incoherent crystallographic orientation relationships (COR), defined by perfect edge-to-edge matching, as well as slight (2–4º) to significant (45º) lattice misfit. These COR suggest diverse mechanisms of crystal growth of Cu-Fe-Ni sulfide melt mechanically trapped by growing laurite. Meanwhile, the mutual COR within the sulfide inclusions discloses: (1) Fe-Ni-S melt solidified into MSS re-equilibrated after cooling into pyrrhotite ± pentlandite, (2) Cu-Ni-Fe-S melts crystallized into the quaternary solid solution spanning the compositional range between heazlewoodite [(Ni, Fe)3±xS2] (Hzss) and ISS [(Cu1±x, Fe1±y)S2]. Additionally, nanocrystallites (50–100 nm) of Pt-S and iridarsenite (IrAsS) accompanying the sulfide inclusions spotlight the segregation of PGE-rich sulfide and arsenide melt earlier and/or contemporarily to laurite crystallization from the silicate magmas. Cobaltite (CoAsS)-gersdorffite (NiAsS) epitaxially overgrown on laurite further supports the segregation of arsenide melts at early stages of chromitite formation.
PB Springer
SN 0026-4598
YR 2024
FD 2024-06-26
LK https://hdl.handle.net/20.500.14352/119409
UL https://hdl.handle.net/20.500.14352/119409
LA eng
NO González-Jiménez, J. M., González-Pérez, I., Plissart, G., Ferreira, A. R., Schettino, E., Yesares, L., Schilling, M. E., Corgne, A., & Gervilla, F. (2025). Micron-to-nanoscale investigation of Cu-Fe-Ni sulfide inclusions within laurite (Ru, os)S2 from chromitites. Mineralium Deposita, 60(2-3), 581-604. https://doi.org/10.1007/s00126-024-01285-0
NO Ministerio de Ciencia e Innovación
NO European Union
NO Chilean National Research and Development Agency
DS Docta Complutense
RD 21 ene 2026