Paleoproterozoic Positive delta C-13 Excursion in Henan, China

A positive delta C-13 excursion in Palaeoproterozoic carbonate sequences in Henan, China is reported in this paper. Carbon isotope analyses of samples from Wuzhiling and Huayu Formation of Songshan Group, a well-preserved Palaeoproterozoic-carbonate sequences in northern Henan, China present delta C-13 values range from -1.0 parts per thousand to 4.2 parts per thousand(PDB), with a mean at 2.5 parts per thousand(PDB). Results of microscope observation, oxygen isotope, and Mn/Sr ratio indicate that Wuzhiling Formation suffered stronger alternation than Huayu, which suggested a higher initial delta C-13 excursion of Wuzhiling Formation than present known value. The positive delta C-13(carb) excursions of Wuzhiling Formation support the Lamagundi Event as early oxygenation of the terrestrial environment, was also recorded in Palaeoproterozoic carbonate sequences in Henan, China.Environmental SciencesGeosciences, MultidisciplinarySCI(E)1ARTICLE3,SI287-2982