Geochemical Modeling of Species-Specific Vital Effects in Planktonic Foraminifera
Abstract
Foraminiferal stable isotopes form a primary proxy archive for paleoceanographic reconstructions. In benthic foraminifera, the existence of species-specific "vital effects" is well-documented and corrections are applied to reconcile isotope records across species. Yet in planktonic foraminifera, many paleoceanographic interpretations depend on the assumption that isotope signatures in mature foraminifera are produced solely by environmental variables such as seawater chemistry, depth of calcification, and the presence of symbiotic algae, without significant additional species-specific effects. This is despite recent statistical evidence suggesting that isotope data from planktonic foraminifera is best explained by allowing for species-specific effects beyond symbiont and depth ecology (Edgar et al., 2017). Here, we present a new geochemical model that simulates the accretion of calcite over the entire lifecycle of a foraminifer in a continuous simulated 1D water-column. We compare simulated populations to real-world tow and sediment trap data to test the assumption that seawater chemistry and ontogenetic depth preferences are sufficient to explain real-world foraminiferal δ13C and assess the degree to which differences in basal metabolic rates between clades can explain species-specific vital effects.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMPP43A..06G
- Keywords:
-
- 0419 Biomineralization;
- BIOGEOSCIENCESDE: 0473 Paleoclimatology and paleoceanography;
- BIOGEOSCIENCESDE: 4924 Geochemical tracers;
- PALEOCEANOGRAPHYDE: 4994 Instruments and techniques;
- PALEOCEANOGRAPHY