Sara Milner

BG Biogeosciences

The 2017 Outstanding Student Poster and PICO (OSPP) Award is awarded to Sara Milner for the poster/PICO entitled:

Assessing the biomineralization processes in the shell microstructure of modern brachiopods: variations in the oxygen isotope composition and minor element ratios (Milner, S.; Rollion-Bard, C.; Burckel, P.; Tomasovych, A.; Angiolini, L.; Henkel, D.;)

Click here to download the poster/PICO file.

I am a PhD student at the Geochemistry department at the Institute de Physique du Globe de Paris, France. I am part of the ITN BASE-LiNE Earth Project (Brachiopods As SEnsitive tracers of gLobal mariNe Environment: Insights from alkaline, alkaline Earth metal, and metalloid trace element ratios and isotope systems). The goal of my PhD is to determine the biomineralization processes related to brachiopod shell formation and their impact on geochemical proxies in brachiopods. For this, I analyze different isotopic systems (oxygen, carbon, boron and calcium) and trace element ratios (Li/Ca, B/Ca, Na/Ca, Mg/Ca and Sr/Ca) in the shell microstructure of modern brachiopods and evaluate which brachiopod taxa and shell microstructure is the most suitable to use as chemical proxies of paleo-seawater.

In the poster I presented at the EGU 2017 I show the oxygen isotopic composition and trace element ratios in the shell microstructure of eight modern brachiopod species. For this, I analyzed the at the micrometer scale with the ion probe (δ18O) and laser ablation (trace elements) and compare them with calcite precipitated inorganically, in order to evaluate which are the shell microstructure or portions that are in equilibrium with inorganic calcite, and thus, the most reliable for paleoenvironmental studies.