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

704216.pdf (8.19 MB)

Document type

Article

Version

Published version

Publication date

2020-06-05

Publication license

cc-by (c) Cruset Segura, David et al., 2020
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/174179

Significance of Fracture-Filling Rose-Like Calcite Crystal Clusters in the SE Pyrenees

Journal Title

Authors

Director/Tutor

Journal ISSN

Volume Title

Related resource

https://doi.org/10.3390/min10060522

Abstract

Fracture-filling rose-like clusters of bladed calcite crystals are found in the northern sector of the Cadí thrust sheet (SE Pyrenees). This unusual calcite crystal morphology has been characterized by using optical and electron microscope, X-ray diffraction, Raman spectroscopy, 18O, 13C, 87Sr/86Sr, clumped isotopes, and major and rare earth elements + yttrium (REEs + Y) analysis. Petrographic observations and powder X-ray diffraction measurements indicate that these bladed crystals are mainly made of massive rhombic crystals with the conventional (104) faces, as well as of possibly younger, less abundant, and smaller laminar crystals displaying (108) and/or (108) rhombic faces. Raman analysis of liquid fluid inclusions indicates the presence of aromatic hydrocarbons and occasionally alkanes. Clumped isotopes thermometry reflects that bladed calcite precipitated from meteoric fluids at ~60-65 C. The 87Sr/86Sr ratios and major elements and REEs content of calcite indicate that these fluids interacted with Eocene marine carbonates. The presence of younger 'nailhead' calcite indicates later migration of shallow fresh groundwater. The results reveal that rose-like calcite clusters precipitated, at least in the studied area, due to a CO2 release by boiling of meteoric waters that mixed with benzene and aromatic hydrocarbons. This mixing decreased the boiling temperature at ~60-65 C. The results also suggest that the high Sr content in calcite, and probably the presence of proteins within hydrocarbons trapped in fluid inclusions, controlled the precipitation of bladed crystals with (104) rhombohedral faces.

Subject

Morfologia (Biologia), Calcita

Subject (English)

Morphology (Biology), Calcite

Citation

Collections

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

Citation

CRUSET SEGURA, David, et al. Significance of Fracture-Filling Rose-Like Calcite Crystal Clusters in the SE Pyrenees. Minerals. 2020. Vol. 10, num. 6. ISSN 2075-163X. [consulted: 11 of August of 2026]. Available at: https://hdl.handle.net/2445/174179

Export metadata

JSON - METS

Share record