High-resolution δ13Corg chemostratigraphy links the Decorah impact structure and Winneshiek Konservat-Lagerstätte to the Darriwilian (Middle Ordovician) global peak influx of meteorites
The precise age of the Winneshiek Shale, a recently discovered Konservat-Lagerstätte located in a very unusual depositional setting inside the Decorah impact structure, has remained uncertain in the absence of biostratigraphically highly diagnostic fossils. This chemostratigraphical study, based on δ13Corg data from 36 drill core samples through the shale, shows that the age ranges from the upper
