Bulk-carbonate and belemnite carbon-isotope records across the Pliensbachian-Toarcian boundary on the northern margin of Gondwana (Issouka, Middle Atlas, Morocco)
A negative carbon isotope excursion at the Pliensbachian–Toarcian boundary Belemnite records show positive carbon isotope values. Data suggest spatial heterogeneity of the Early Jurassic ocean. Patterns consistent with volcanic outgassing as a trigger of the boundary event We propose a regional change in the source of the carbonate carrying to a negative carbon isotope in micrite signature.