Lower Ordovician carbon isotope excursion in the eastern Yangtze Gorges area and its genetic analysis

The carbon stable isotope curve was constructed in this paper from the Huanghuachang sections of Lower Ordovician in the eastern Yangtze Gorges area.δ¹³C data demonstrate that there existed two δ¹³C positive excursions (C1, C3) and two negative excursions (C2, C4), all of which are comparable in the global scale.Based on the sedimentary sequence characteristics of Lower Or-dovician in the eastern Yangtze Gorges area, the authors observed that the curve of δ¹³C is coincident with the curve of the regional sea-level fluctuations.This study indicates that the geochemistry as well as the sequences was well controlled by the sea level changes.