Amb motiu del tancament d'estiu, la validació de documents es reprendrà a partir del 28 d'agost de 2026. Disculpeu les molèsties.
Con motivo del cierre de verano, la validación de documentos se reanudará a partir del 28 de agosto de 2026. Disculpad las molestias
Due to the summer closure, document validation will resume starting August 28, 2026. We apologize for any inconvenience.

Files

690025.pdf (4.46 MB)

Document type

Article

Version

Published version

Publication date

2019-05-11

Publication license

cc-by (c) Baurier Aymat, Sandra et al., 2019
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/157421

Nanoscale Structure of Zoned Laurites from the Ojén Ultramafic Massif, Southern Spain

Journal Title

Authors

Director/Tutor

Journal ISSN

Volume Title

Related resource

https://doi.org/10.3390/min9050288

Abstract

We report the first results of a combined focused ion beam and high-resolution transmission electron microscopy (FIB/HRTEM) investigation of zoned laurite (RuS2)-erlichmanite (OS2) in mantle-hosted chromitites. These platinum-group minerals form isolated inclusions (<50 µm across) within larger crystals of unaltered chromite form the Ojén ultramafic massif (southern Spain). High-magnification electron microscopy (HMEM), high angle-annular dark field (HAADF) and precession electron diffraction (PED) data revealed that microscale normal zoning in laurite consisting of Os-poor core and Os-rich rims observed by conventional micro-analytical techniques like field emission scanning electron microscope and electron microprobe analysis (FE-SEM and EPMA) exist at the nanoscale approach in single laurite crystals. At the nanoscale, Os poor cores consist of relatively homogenous pure laurite (RuS2) lacking defects in the crystal lattice, whereas the Os-richer rim consists of homogenous laurite matrix hosting fringes (10-20 nm thickness) of almost pure erlichmanite (OsS2). Core-to-rim microscale zoning in laurite reflects a nonequilibrium during laurite crystal growth, which hampered the intra-crystalline diffusion of Os. The origin of zoning in laurite is related to the formation of the chromitites in the Earth's upper mantle but fast cooling of the chromite-laurite magmatic system associated to fast exhumation of the rocks would prevent the effective dissolution of Os in the laurite even at high temperatures (~1200 °C), allowing the formation/preservation of nanoscale domains of erlichmanite in laurite. Our observation highlights for the first time the importance of nanoscale studies for a better understanding of the genesis of platinum-group minerals in magmatic ore-forming systems.

Subject

Minerals de platí, Ions, Microscòpia electrònica de transmissió, Difracció d'electrons

Subject (English)

Platinum ores, Ions, Transmission electron microscopy, Electrons diffraction

Citation

Collections

Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)

Citation

BAURIER AYMAT, Sandra, et al. Nanoscale Structure of Zoned Laurites from the Ojén Ultramafic Massif, Southern Spain. Minerals. 2019. Vol. 9, num. 5, pags. 288. ISSN 2075-163X. [consulted: 12 of August of 2026]. Available at: https://hdl.handle.net/2445/157421

Export metadata

JSON - METS

Share record