CO2 species released by local decomposition of organic matter ... JSTOR
normal coalball samples were relatively depleted in 13C (20 to 23 permil rel. PDB). This evidence indicated that isotopicallyenriched marine, inorganic carbon was an important source of carbonate in faunaltype coal balls and that isotopicallydepleted carbon from plant decomposition was the major source of carbonate in normal coal balls.