Marine microorganisms as amber inclusions: actuo-palaeontological data from the littoral forests of New Caledonia

Alexander R. Schmidt (1) , Grabow D. , Christina Beimforde (1) , Vincent Perrichot (2) , Jouko Rikkinen (3) , Simona Saint-Martin (4) , V. Thiel (5) , Leyla J. Seyfullah (6)

1 Courant Research Centre Geobiology
2 GR - Géosciences Rennes
3 Faculty of Biological and Environmental Sciences [Helsinki]
4 Paléobiodiversité et paléoenvironnements
5 Geoscience Centre (GZG)
6 School of Geography, Earth and Environmental Sciences, University of Birmingham

Marine microorganisms trapped in amber are extremely rare in the fossil record, but are a very unexpected occurrence. Several different scenarios have been proposed to explain how these marine inclusions can become trapped in a resin of terrestrial origin. The marine inclusions reported to date originate from very few pieces of Cretaceous amber from France, and a coastal setting for the amber source forests is generally proposed. However, there are conflicting suggestions about the conditions required for the marine inclusions to become entrapped in amber. These include: through high tides, directly blown in by the wind or from sea spray, or storms and flooding of the littoral/estuarine forest floor or mangroves where the resin dropped into the sea trapping marine organisms. We tested the wind-blown and sea spray suggestions using a modern highly resinous coastal forest domnated by Araucaria columnaris in New Caledonia as a model for the Cretaceous amber deposits from France. We exposed fresh resin surfaces on the seaward side of the trees and collected older in situ resins, and then examined them both. Marine microorganisms did become trapped on the freshly exposed resin, along with remnants from terrestrial organisms, and salt crystals. We suggest that for cases where only one or two marine inclusions are discovered in a deposit, an aeolian origin is most likely; however, a more energetic but possibly still aeolian event is likely to be needed to be able to embed the high numbers of marine organisms recorded from only two pieces of amber.

Domains: Paleontology

Alexander R. Schmidt, Grabow D., Christina Beimforde, Vincent Perrichot, Jouko Rikkinen, et al.. Marine microorganisms as amber inclusions: actuo-palaeontological data from the littoral forests of New Caledonia. 26th International Plant Taphonomy Workshop, Nov 2017, Göttingen, Germany. ⟨insu-01715208⟩