Experimental Dissolution of Pliocene Diatoms
Mikkelsen, Naja
Nova Hedwigia Band 33 Heft 1-4 (1980), p. 893 - 911
26 références bibliographiques
publié: Feb 26, 1980
DOI: 10.1127/nova.hedwigia/33/1980/893
ArtNo. ESP050003300031, Prix: 29.00 €
Abstract
Four Pliocene diatom assemblages, representing different paleooceanographic environments in the Pacific, were subjected to experimentally controlled dissolution in natural seawater. Afterwards, the fossil species of each assemblage were ranked according to their relative dissolution resistance, and a tentative correlation esiablished between the rankings. The correlation suggests an intraspecific variation with latitude in the dissolution resistance of the diatoms. The basic structure of the diatom valves determined the change in valve morphologies with dissolution. The rate at which these changes occurred varied from species to species. Smaller specimens of most diatom species were removed from the assemblages in the initial phase of the dissolution process, and fragmentation of the diatom valves increased with time of exposure to the seawater. Radiolarians were the group of siliceous microfossils most resistant to dissolution. Diatoms were considerably less resistant and silicoflagellates appeared to be the group most susceptible to dissolution.
Mots-clefs
natural seawater • fossil species • intraspecific variation • latitude • valve morphologies • dissolution resistance • siliceous microfossils