Nitrogen isotope compositions of the Upper Triassic Chang 7 Shale, Ordos Basin, North China: Implications for depositional redox conditions

Nitrogen isotope (δ15N) analysis has been used to evaluate depositional redox conditions in well-preserved sedimentary systems; however, fewer N-isotope studies have been performed to reconstruct the redox conditions in lacustrine shales. In this paper, we report the δ15N data from the Upper Triassic Chang 7 Shale of the Ordos Basin, North China. Sedimentary δ15N values are significantly higher in the Chang 73 and the lower part of the Chang 72...