Table 4.

An Attempt to Highlight the Fact That Terminology Is Missing for Organic Compounds Resulting from Mixed Processes and Carbon Source

Source	Abiogenic	Biogenic
Processes	(ex: mantle CO2)	(microbial production and organic matter degradation)
Abiogenic (ex: FTT)	Abiogenic	?
Biogenic (ex: methanogens)	?	Biogenic
Thermogenic (ex: cracking)	?	Thermogenic

For example, a molecule resulting from FTT reaction using mantle CO₂ will be called abiogenic. If the same process uses CO₂ from respiration (although we do not know if this kind of reaction can actually occur, so we beg the reader to take this as an illustration), we currently do not know what to call the resulting product, which would be biogenic with respect to the source and abiogenic with respect to the process. Boxes left with a ? point out the word missing.