Reconstructing Modern and LGM Water Column Hydrography Using Stable Isotopes of Single Specimens of Multiple Planktic Foraminifera

J. S. Fehrenbacher, Howard J. Spero, L. Vetter, C. V. Davis, J. M. Griffin, B. L. Grimm, P. Kercher, M. Kostlan, Anthony J. Menicucci, L. Santare, M. Wildgoose, J. Starnes, E. Wilbanks

Research output: Contribution to conferencePoster

Abstract

Oxygen and carbon isotope data from planktic foraminifera play an important role in paleoceanographic reconstructions of temperature, salinity, and nutrients. Typically, such analyses are conducted using multiple shells of the same species. However, important habitat depth and seasonal information are lost in pooled shell analyses. In this study, we have analyzed the δ 18 O and δ 13 C of single specimens of different species of planktic foraminifera including G. ruber (pink & white var.), G. sacculifer, O. universa, G. siphonifera, S. dehiscens, G. conglobatus, G. menardii, N. dutertrei, P. obliquiloculata, G. truncatulinoides and G. tumida from a western Caribbean core (OPDP 999A) and eastern equatorial Pacific (EEP) core (TR163-19). We use the average species δ 18 O values to estimate mean depth habitats and, for comparison purposes, normalize each species δ18O values to the δ18O:temperature relationship of G. ruber/O. universa (Bemis et al., 1998; Thunell et al, 2000). In order to compare δ 13 CDIC through time and space, we develop δ 13 C ‘corrections’ to normalize the δ 13 CFORAM values to the modern δ 13 CDIC for each core site. We find that both δ 18 O and δ 13 C normalization for each species varies between sites and attribute this variation to water column differences in [CO32-] between the Caribbean and EEP. We explore employing these corrections through time by applying the modern corrections to LGM δ 13 C /δ 18 O data. This multispecies, individual shell analysis approach may provide a method to infer changes in upper water column δ 18 OSW and δ 13 CDIC gradients through time.

Original languageAmerican English
StatePublished - Jan 1 2013
Externally publishedYes
EventAGU Fall Meeting -
Duration: Dec 13 2019 → …

Conference

ConferenceAGU Fall Meeting
Period12/13/19 → …

Disciplines

  • Earth Sciences

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