The CHNs of organic geochemistry: characterization of molecularly uncharacterized non-living organic matter

摘要

For decades, perhaps centuries, organic geochem-ists have struggled to define and characterize what usually constitutes the major fraction of organic matter in sediments, soils, and natural waters—what is referred to as molecularly uncharacterized carbon (MUC). This material derives from the decay of plant remains but retains only minor components of those original plants, at least as far as has been detected using techniques currently available to organic geo-chemists. Living plant constituents that can easily be identified and quantified (carbohydrates, proteins, lipids) constitute the bulk of recognizable organic matter in moribund plant remains. In a relatively short period of time, days to years, a transformation occurs to substances that are not easily recognized (Hedges et al., 2000).