Long-term, low temperature simulation of early diagenetic alterations of organic matter: A FTIR study

Abstract

Early diagenetic alterations of organic matter from conifers and algae were simulated at 80°C for more than five years. To investigate the changes of functional groups of organic matter during the simulation, the samples were analysed by Fourier Transform Infrared (FTIR) spectroscopy. The basic IR spectra characteristics of coniferous and algal organic matter were elaborated. The results indicate that only the IR absorptions from aromatic rings are different. The changes of IR spectra of simulated samples show that organic matters underwent dehydroxylation, decarboxylation or polycondensation during the simulation. Besides, the differences of IR spectra among selected samples under different conditions reveal that iron-containing environment may deplete the phenolic hydroxyls in conifer samples, and the hypersaline conditions can accelerate the degradation of asphaltenes into polar compounds both in conifers and algae samples.