"SIMS"

Large isotopic variability at the micron-scale in ‘Shuram’ excursion carbonates from South Australia

Ediacaran-aged (635–541 million years ago) marine sediments contain a large negative carbon isotope (δ13C) excursion, in which carbonate δ13C values reach −12‰ (VPDB). Known as the ‘Shuram’ excursion, many workers have interpreted this δ13C record as …