Resolved measurements of <SUP>13</SUP>CDH₃ and <SUP>12</SUP>CD₂H₂ from a mud volcano in Taiwan

Resolved measurements of the relative abundances of (CDH3)-C-13 and (CD2H2)-C-12 from a Taiwan mud volcano confirm that thermogenic CH4 with a formation temperature of 150 degrees C is bubbling from a pool of liquid mud. Analysis for both doubly-substituted molecules provides confirmation that isotopic exchange equilibrium was achieved between methane isotopologues. Methane extracted from the headspace of core samples taken from sediments deposited proximal to the bubbling pool of mud shows small departures from isotopic equilibrium.