Abstract
The study of the structural order of charcoals embedded in pyroclastic density currents provides information on their emplacement temperature during volcanic eruptions. In the present work, a set of charcoals from three distinct pyroclastic density currents deposits whose temperatures have been previously estimated by charcoal reflectance analyses to lie between 250 °C and 550 °C, was studied by means of Raman spectroscopy. The analyses reveal a very disordered structural ordering of the charcoals, similar to kerogen matured under diagenetic conditions. Changes in Raman spectra at increasing temperatures reflect depolymerization and an increase of aromaticity and can be expressed by parameters derived from a simplified fitting method. Based on this approach, a second order polynomial regression with a high degree of correlation and a minimum error was derived to predict paleotemperatures of pyroclastic deposits. Our results show that Raman spectroscopy can provide a reliable and powerful tool for volcanological studies and volcanic hazard assessment given its advantage of minimum samples preparation, rapid acquisition processes and high precision.
Original language | English |
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Article number | 203 |
Number of pages | 19 |
Journal | Minerals |
Volume | 12 |
Issue number | 2 |
Early online date | 5 Feb 2022 |
DOIs | |
Publication status | Published - 5 Feb 2022 |
Bibliographical note
The Grant of Excellence Departments, MIUR (ARTICOLO 1, COMMI 314–337 LEGGE 232/2016) is gratefully acknowledged. MathWorks is acknowledged for providing the Matlab license for this work. A version of the script for calculating temperatures from Raman spectra can be provided by the authors upon request.This research was funded by an MIUR Roma Tre post-doctoral grant (2017–20) No. REP. 22-PROT. 219 of 26 January 2017.
Data Availability Statement
All data are reported in the manuscript and Supplementary MaterialsKeywords
- Charcoal
- Charcoal reflectance
- Multivariate polynomial regression
- Pyroclastic density currents
- Raman spectroscopy