Geology Commons^™

Relationship Between Individual Chamber And Whole Shell Mg/Ca Ratios In Trilobatus Sacculifer And Implications For Individual Foraminifera Palaeoceanographic Reconstructions, Gerald T. Rustic, Pratigya J. Polissar, Ana Christina Ravelo, Peter Demenocal

School of Earth & Environment Faculty Scholarship

Precisely targeted measurements of trace elements using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) reveal inter-chamber heterogeneities in specimens of the planktic foraminifer Trilobatus (Globigerinoides) sacculifer. We find that Mg/Ca ratios in the final growth chamber are generally lower compared to previous growth chambers, but final chamber Mg/Ca is elevated in one of thirteen sample intervals. Differences in distributions of Mg/Ca values from separate growth chambers are observed, occurring most often at lower Mg/Ca values, suggesting that single-chamber measurements may not be reflective of the specimen’s integrated Mg/Ca. We compared LA-ICPMS Mg/Ca values to paired, same-individual Mg/Ca measured via …