• journal_title：Geology
• Contributor：Dan J. Charman ; Ramon Aravena ; Charlotte L. Bryant ; Doug D. Harkness
• Publisher：Geological Society of America
• Date：1999-
• Format：text/html
• Language：en
• Identifier：10.1130/0091-7613(1999)027<0539:CIIPDC>2.3.CO;2
• journal_abbrev：Geology
• issn：0091-7613
• volume：27
• issue：6
• firstpage：539

Carbon gases with younger ¹⁴C ages than those of the surrounding peat have been reported from continental boreal peatlands, a fact which suggests that significant movement of CO₂, CH₄, or DOC (dissolved organic carbon) and export of C via subsurface processes are not accounted for in most estimates of contributions to the C cycle. This paper tests the hypothesis that similar processes can occur in oceanic ombrotrophic mires where water and gas movement is theoretically minimal. Measurements of ¹⁴C and δ¹³C in CO₂, CH₄, and DOC, and of tritium, are reported from depths to 250 cm at Tor Royal, a raised mire in southwest England. Radiocarbon ages of gases are 1460 to 500 yr younger than those of peat from the same depths, and CO₂ is consistently younger than CH₄. DOC is 1260 to 830 yr younger than the peat, and significant amounts of tritium were found at all depths. Gas ages are mostly intermediate between the age of the peat and that of the DOC, which suggests that C is principally transported as DOC. However, some gases are younger than their associated DOC, which implies that movement of dissolved gases may also take place. δ¹³C values in gases suggest that CO₂ reduction is the major pathway for CH₄ production. Transport of C in deep peats is likely to be a significant component in the overall C budget of ombrotrophic oceanic peatlands, and C export via discharge to ground or surface waters may be an important mechanism for gaseous C emissions.