Lacustrine sedimentary record of early Aptian carbon cycle perturbation in western Liaoning, China

The early Aptian abrupt carbon isotope excursion in marine carbonate and sedimentary organic matter reflects a major perturbation in the global carbon cycle. However, until now almost all the evidences of this event came from marine deposits. Here we present organic-carbon isotope (delta C-13(org)) data from the non-marine Jehol Group in western Liaoning, China. The lacustrine delta C-13(org) curve is marked by a relative long-lasting delta C-13(org) minimum followed by two stages of positive delta C-13(org) excursions that are well correlated with contemporaneous marine records. The carbon isotope correlation shows that the lacustrine strata of the Jehol Group were deposited at the same time of the early Aptian Oceanic Anoxic Event (OAE1a). The relative long-lasting delta C-13(org) minimum supports the hypothesis that volcanic CO2 emission may have played the main role in triggering the negative delta C-13(org) excursion and global warming at the onset of this event. In addition, the onset of delta C-13(org) minimum is concomitant with the radiation of the Jehol Biota, implying that the evolutionary radiation of the Jehol Biota may have been closely related with the increase in atmospheric CO2 and temperature. (C) 2015 Elsevier Ltd. All rights reserved.