GLOBAL OCEAN ACIDIFICATION IN THE AFTERMATH OF THE MARINOAN GLACIATION
Cap dolomites of the Yangtze Platform (South China block), Kazakhstan and Namibia (Kalahari and Congo craton) show similar B isotope and hence similar ocean-pH pattern although the nadir in ocean acidification differs between the investigated cratons/blocks. Of all blocks, the most pronounced negative excursions of -12‰ in δ11B and down to -6‰ in δ13C, occur in Namibia (Congo Craton, Kasemann et al., 2010) and South China whereas a drop from 8.0 to 1.8‰ in δ11B and down to ‑3‰ in δ13C is visible in Kazakhstan (Malyi Karatau range). Therefore, a transient decrease by >1 pH units down to a minimum ocean-pH of about 7 during deglaciation is indicated.
Our approach of a multi craton correlation provides evidence for a global ocean acidification event, potentially associated with enhanced atmospheric pCO2 during time of deglaciation.
 Hoffman et al. (1998) Science 281, 1342–1346.
 Kasemann et al. (2010) Geology 38, 775-778.