Radiocarbon dating of highly degraded and problematic fossil wood: verification of the effectiveness of various preparation methods

ABSTRACT This paper compares various wood pretreatment methods for highly degraded, and problematic fossil wood extracted from the opencast Szczerców site of the Bełchatów Lignite Mine in Central Poland. The study evaluates the pretreatment methods using both large samples (55–255 g, referred to as series A) and small samples (36–150 mg, referred to as series B). Additionally, all preparation methods were applied to medium-sized samples (approximately 3 g, referred to as series C) with solvent washes in the Soxhlet apparatus. Radiocarbon dating was conducted using the LSC technique (subseries A1) and the AMS technique (subseries A2, series B, and C). The effectiveness and utility of each pretreatment protocol were compared based on 14C measurements and FTIR analysis. Through the conducted research and a multi-criteria analysis, the most effective method for preparing old fossil wood was identified. Our experience indicates that an extended, multistage preparation of highly degraded fossil wood samples, with a 14C concentration near the detection limit of the radiocarbon method, may result in a significant increase in 14C content.