Geochemical calibration of the petrographic gelification axis in coals: dataset and reproducible workflow

This deposit contains data, code, results, figures, and documentation for the geochemical calibration of the petrographic gelification axis in coals. This deposit contains data, code, results, figures, and documentation for the geochemical calibration of the petrographic gelification axis in coals. -------------------------------------------------- SOURCE DATA Tewalt, S.J., et al. (2010). Chemical analyses in the World Coal Quality Inventory, version 1.0. USGS Open-File Report 2010-1196.https://doi.org/10.3133/ofr20101196 This dataset is derived from a subset of 65 samples from the WoCQI database. -------------------------------------------------- CONTENTS - petro_clean.xlsx : input data (65 samples, 44 elements)- petro_clean_full.xlsx : extended version with metadata- calibrate_coal_gelification_multimodel.py : Python code- coal_gelification_multimodel_results.xlsx : complete results (28 sheets)- Supplementary_Results_and_Interpretation.pdf : full interpretation- figures/ : 9 publication-ready PNG figures -------------------------------------------------- METHODS P-axis (gelification): P = ln((G+0.5)/(T+0.5)) Log-contrast correction: Al–Si–Ti background Z-scores: standardized contrast with bootstrap 95% CI (2000 iterations) Rmax-axis: based on measured Rmax values only (Rrandom not merged) -------------------------------------------------- KEY FINDING Gelification and coal rank represent distinct but partially overlapping geochemical axes: Gelification ≠ Rank Gelification ∩ Rank = redox-sulfidic + fluid-mobile components Be is associated with the gelification axis, whereas U is associated with the rank (Rmax) axis. -------------------------------------------------- REPRODUCIBILITY Run:python calibrate_coal_gelification_multimodel.py -------------------------------------------------- LICENSE CC BY 4.0 -------------------------------------------------- VERSION 1.0 (2026-04-30) -------------------------------------------------- CONTACT Olga Shagarova Email: [e-mail] ORCID: 0009-0007-8195-5827