A continental record of the late Campanian negative carbon isotopic excursion (LCE, late Campanian event) in the Dinosaur Park Formation, Alberta, Canada

The Campanian was the longest stage of the Late Cretaceous and witnessed multiple global carbon cycle disruption episodes, including the negative carbon isotope excursion (CIE) known as the Late Campanian Event (LCE). However, Campanian-aged δ 13 C perturbations are primarily documented in marine environments, raising questions about their record in terrestrial settings and the potential use of terrestrial stable carbon isotope records from the Campanian as a chemostratigraphic tool. In this study, we present a stable carbon isotope record from fossil organic matter preserved in the alluvial floodplains of the Dinosaur Park Formation, which is radiometrically dated to the time interval containing the LCE. Results reveal a ∼ 0.8 ‰ negative CIE recorded in floodplain fossil organic matter. We show that the negative CIE is not a result of changing organic matter or diagenesis and that it likely reflects the global atmospheric δ 13 C signal during the Campanian. We interpreted the identified negative CIE as a continental record of the LCE. When we couple our δ 13 C TOC record with the Dinosaur Park Formation’s age model, we can correlate our section with other well-dated European marine stratigraphic sections. Our findings demonstrate that Campanian carbon cycle perturbations are preserved in terrestrial environments. For the first time, we recognize that the deposition of the world-famous dinosaur-bearing Dinosaur Park Formation in Alberta was contemporaneous with a major global carbon cycle perturbation episode. Our findings contribute to contextualizing ongoing research and re-evaluating previous studies on dinosaur evolution and other contemporary groups, within the framework of planetary-scale Earth system disturbances. • The Dinosaur Park Formation (DPF) records a global δ 13 Cᴛᴏᴄ signal. • Deposition of the lower portion of the DPF was contemporaneous with the LCE. • Floodplains of the DPF serve as a chemostratigraphic tool for the late Campanian.