What controls {delta}{sup 13}C(CH{sub 4}) and {delta}D(CH{sub 4}) of peat gases?

Conference · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:370457

Waldron, S; Fallick, A E; Hall, A J ^[1]

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1. Univ. of Glasgow (United Kingdom)

{delta}{sup 13}C(CH{sub 4}), {delta}{sup 13}C(CO{sub 2}) and {delta}D(CH{sub 4}) of bacteriogenic CH{sub 4} and CO{sub 2} from Ellergower Moss, a raised peat bog in S.W. Scotland were measured from gas samples collected in situ, from two profiles, at 1 m intervals, from the surface to a depth of 5 m. {delta}{sup 13}C(CH{sub 4}) had a mean of -76{plus_minus}3{per_thousand}, {delta}{sup 13}C(CO{sub 2}) had a mean of 3.8{plus_minus}5.3{per_thousand}, {delta}D(CH{sub 4}) had a mean of -294{plus_minus}39{per_thousand}. In each profile {delta}{sup 13}C(CH{sub 4}), {delta}{sup 13}C(CO{sub 2}) arid {delta}D(CH{sub 4}) showed a general gradation from isotopically heavy at 5 m depth to isotopically light at the surface. {delta}D(CH{sub 4}) suggested the presence of a boundary between 2-3 m as the measured values from 3-5 m were 52{plus_minus}18{per_thousand} heavier than samples from 0-2 m. Such a difference was also observed with {delta}{sup 13}C(CH{sub 4}) and {delta}{sup 13}C(CO{sub 2}) measurements. One possibility is that the observed differences in isotopic profiles within the bog were substrate controlled. However {delta}{sup 13}C and {delta}D measurements of peat and porewater reveal this to be unlikely. Rather {delta}{sup 13}C(CH{sub 4}), {delta}{sup 13}C(CO{sub 2}) and {delta}D(CH{sub 4}) may be controlled by gas storage and release mechanisms within the bog.

• OSTI ID: 370457
• Report Number(s): CONF-960376--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CARBON 13
CARBON DIOXIDE
DEUTERIUM
METHANE
PEAT
SAMPLING
SWAMPS