TY - JOUR

T1 - Graphite thermometry by interactive fitting of Raman spectra

AU - Rantitsch, Gerd

PY - 2023/3/31

Y1 - 2023/3/31

N2 - The growth conditions of natural graphite crystals are conventionally estimated by the application of petrological methods on the host rocks. As Raman Spectroscopy records detailed information on the microstructure of a carbon-material, this method is applied empirically to graphite from the southern margin of the Bohemian Massif to investigate the correlation between microstructure and metamorphic peak conditions directly, characterizing an economically important geomaterial. Automated fitting of the second-order Raman-spectrum of graphite assesses the strongly asymmetrical S2-band at ca. 2700 cm−1 by a shape parameter, characterizing the microstructural state of graphite. Applying this concept, a confident parameter (S2-shape) estimates the peak metamorphic temperature of natural graphite crystals between 600 °C and 800 °C. The application in the southern Bohemian Massif maps metamorphic peak temperatures related to Variscan tectonics. Comparing the microstructure of large crystals from graphite seams with tiny crystals dispersed in the rock matrix, there is evidence that small graphite particles are not influenced by a late-stage overprint.

AB - The growth conditions of natural graphite crystals are conventionally estimated by the application of petrological methods on the host rocks. As Raman Spectroscopy records detailed information on the microstructure of a carbon-material, this method is applied empirically to graphite from the southern margin of the Bohemian Massif to investigate the correlation between microstructure and metamorphic peak conditions directly, characterizing an economically important geomaterial. Automated fitting of the second-order Raman-spectrum of graphite assesses the strongly asymmetrical S2-band at ca. 2700 cm−1 by a shape parameter, characterizing the microstructural state of graphite. Applying this concept, a confident parameter (S2-shape) estimates the peak metamorphic temperature of natural graphite crystals between 600 °C and 800 °C. The application in the southern Bohemian Massif maps metamorphic peak temperatures related to Variscan tectonics. Comparing the microstructure of large crystals from graphite seams with tiny crystals dispersed in the rock matrix, there is evidence that small graphite particles are not influenced by a late-stage overprint.

U2 - 10.1016/j.coal.2023.104232

DO - 10.1016/j.coal.2023.104232

M3 - Article

VL - 271.2023

JO - International journal of coal geology

JF - International journal of coal geology

SN - 0166-5162

IS - 15 April

M1 - 104232

ER -