Isotopic signatures of carbon in the ‘Los Pobres’ graphite mine, Ronda, Spain

Autor: Sara Nilsson, Wolf D. Geppert, Curt Broman, Anna Neubeck, Martin J. Whitehouse, Nils Holm, Magnus Ivarsson, Fernando Gervilla
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Neubeck, A, Broman, C, Ivarsson, M, Holm, N G, Whitehouse, M, Nilsson, S, Geppert, W & Gervilla, F 2020, ' Isotopic signatures of carbon in the ‘Los Pobres’ graphite mine, Ronda, Spain ', Journal of Petrology, vol. 61, no. 4, egaa042 . https://doi.org/10.1093/petrology/egaa042
Digibug. Repositorio Institucional de la Universidad de Granada
instname
Digibug: Repositorio Institucional de la Universidad de Granada
Universidad de Granada (UGR)
DOI: 10.1093/petrology/egaa042
Popis: We would like to thank Alison Wright at the University of Aberdeen for Raman measurements, Marianne Ahlbom for guidance with ESEM-EDS, and Heike Siegmund for help with bulk 13C measurements
Graphite formation temperatures in the ‘Los Pobres’ mine within the Ronda peridotite, Spain, previously reported to be between 770 and 820 °C, have been reinterpreted based on new temperature measurements using Raman spectroscopy. Additional in situ and bulk stable carbon isotopic measurements and fluid inclusion studies contributed to improved understanding of parts of the graphite formation process. Raman spectroscopy revealed that the formation of the ‘Los Pobres’ graphite extends to temperatures as low as 500 °C, indicating a broader temperature range than previously reported. Stable carbon isotopes and temperature estimates suggest two different crystallization events, followed by a late hydrothermal alteration of the host rock. The first event occurred at temperatures higher than ∼600°C, in which crystalline graphite was formed with a mixed 13C composition as a result of the mixing of two different carbon-bearing sources. The second graphite formation event took place below ∼600°C, within the same system, but with lower purity and crystallinity of the graphite. In the third event, the temperature decreased to less than 550 °C, and hydrothermal fluids altered the host rock, precipitating silica and iron oxides in veins penetrating both the host rock and the deposited graphite.
Swedish Research Council 2013-7320 2012-4364 2017-05018 2017-04129
Villum Investigator Grant 16518
Databáze: OpenAIRE