Carbon isotope fluctuations through the neoproterozoic-lower Cambrian Birmania basin, Rajasthan, India
摘要:
The results of a carbon isotope study from a hitherto unexplored marine sediments from the Birmania basin, Northwestern India are reported, which documents significant isotope variation across the Precambrian-Cambrian boundary (Pc/C). An attempt has been made to identify carbon isotope chronostratigraphic marker for the Precambrian-Cambrian boundary in the sedimentay succession. The transition is marked by a negative excursion during phosphoritic activity at the base of the Birmania succession which is followed by a positive excursion close to the boundary and a swing back to less positive values in the Early Cambrian. The characteristics of the paleoenvironment during the transition interval is also discussed.