Isn't the soot the carbon we're looking for?
Also,wouldn't extra heavy,extended rainfall cause much of the carbon to be swept into the oceans and possibly be suspended for quite some time?
Carbon Isotope Excursion in Atmospheric CO2 at the Cretaceous-Tertiary Boundary: Evidence from Terrestrial Sediments
Issn: 0883-1351 Journal: PALAIOS Volume: 15 Issue: 4 Pages: 314-322
Authors: ARENS, NAN CRYSTAL, JAHREN, A. HOPE
DOI: 10.1043/0883-1351(2000)015<0314:CIEIAC>2.0.CO;2
ABSTRACT
A carbon isotope excursion immediately above the clay layer that defines the Cretaceous-Tertiary (K/T) boundary has been reported in marine sediments world wide. This paper reports a similar carbon isotope excursion recorded by C3 land plants from three temporally-controlled, stratigraphically-constrained terrestrial sections in the Western Interior of North America (Garfield County, Montana, and Slope County, North Dakota). Carbon isotope measurements of bulk sedimentary organic carbon were well-correlated with those of isolated plant cuticle, suggesting that the terrestrial organic carbon signature in these sediments parallels that of plant cuticle. Carbon isotope signatures were also independent of rock type and depositional environment, showing that the carbon isotope signature of plants, although altered, is not biased taphonomically. Because the signature in terrestrial facies records the isotope composition of paleoatmospheric CO2, this record—combined with that from marine sections—offers additional insight into changes in carbon cycling underlying the K/T negative carbon isotope excursion. For example, radiometric age determinations from the Hell Creek Road locality in Montana bracket the atmospheric carbon isotopic recovery between 65.00 ± 0.05 Ma and 65.16 ± 0.04 Ma. This reflects a more rapid recovery for the terrestrial biosphere than for that of the marine realm, perhaps due to lower extinction rates in land plants than in marine primary producers.