[3] The dark layer of fiskeler,[a] mainly five to ten centimeters thick, clearly marks the Cretaceous–Paleogene boundary and overlies the Maastrichtian age Tor Formation.

[5] The fiskeler is enriched in iridium, a fact used as an argument for the Alvarez hypothesis that the worldwide Cretaceous–Paleogene mass extinction was caused by the impact of an asteroid.

[6] The Rødvig Formation contains a remarkably detailed and complete fossil record of the biota in Northern Europe during the early Paleogene.

[7] A wide variety of benthic foraminifera species have been identified from the Rødvig Formation, with significant differences in abundance across the K–Pg boundary demonstrating the biotic turnover that occurred during the mass extinction event.

[7] The Rødvig Formation was the first known site to document the short-term survival of ammonites into the Paleogene, when they were originally thought to have gone extinct at the K-Pg boundary.