First record of the Eocene pteropod Heliconoides nitens (Gastropoda

Author(s)
J.L. Goedert, J. Peckmann, S.R. Benham, A.W. Janssen
Abstract

Fossils of a single pteropod species were found in an isolated carbonate deposit within middle Eocene deep-water strata of the Humptulips Formation in western Washington State, U.S.A. The carbonate formed at a cold seep where fluids containing high concentrations of hydrocarbons, principally methane, emanated from the seafloor. Anaerobic oxidation of the methane by prokaryotes caused localized and rapid precipitation of calcium carbonate that encased biogenic detritus including wood fragments and mollusk shells; in this case even the minute and delicate aragonitic shells of the pteropod Heliconoides nitens (Lea, 1833), the first certain record of this taxon for the Pacific Basin. The presence of H. nitens in the Humptulips Formation allows us to recalibrate the age of the formation as late Lutetian or early Bartonian, up to 8 million years younger than previously thought. Heliconoides nitens has been found in temporally equivalent strata elsewhere in the world, and this is another example of some fossil pteropods having utility for long distance biostratigraphic correlations. Pteropod shells rapidly dissolve in deep-water environments, thus cold seep deposits may be a source of pteropod fossils in deep-water strata where they otherwise would not occur.

Organisation(s)
Department of Geology
External organisation(s)
Pacific Lutheran University, University of Mary Washington, Naturalis Biodiversity Center
Journal
Proceedings of the Biological Society of Washington
Volume
126
Pages
72-82
No. of pages
11
ISSN
0006-324X
DOI
https://doi.org/10.2988/0006-324X-126.1.72
Publication date
03-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
105121 Sedimentology, 105118 Palaeontology
Portal url
https://ucrisportal.univie.ac.at/en/publications/3f6635ce-dde1-4b6b-ad7d-6a91bfed8776