Simultaneous determination of δ¹¹B and B/Ca ratio in marine biogenic carbonates at nanogram level

verfasst von

Karina Kaczmarek, Ingo Horn, Gernot Nehrke, Jelle Bijma

Abstract

In this study we introduce a new in situ technique which allows the determination of the boron isotopic composition and B/Ca ratios simultaneously at the nanogram level using a combination of optical emission spectroscopy and multiple ion counting MC ICP-MS with laser ablation. This technique offers a new application in the paleo-field of oceanography and climatology since small samples like e.g. single foraminiferal shells can be analyzed. The simultaneous determination of the boron isotopic composition and B/Ca ratios provides two independent proxies which allow the reconstruction of the full carbonate system. To test the new technique we performed measurements on the cultured, benthic foraminifer Amphistegina lessonii. Our results yielded an average boron isotopic composition δ¹¹B=18.0±0.83‰ (SD) with an average internal precision of 0.52‰ (RSE). The boron concentration was 53±7μg/g (SD). These results agree with the range reported in the literature. The reconstructed mean pH value is in excellent agreement with the measured pH of the seawater in which the foraminifers grew. The analysis of a foraminifer consumed approximately 1200. ng calcium carbonate containing ca. 0.06. ng boron. Compared to bulk analytical methods, this new technique requires less material and reduces the time for sample preparation.

Organisationseinheit(en)

Institut für Mineralogie

Externe Organisation(en)

Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung

Typ

Artikel

Journal

Chemical geology

Band

392

Seiten

32-42

Anzahl der Seiten

11

ISSN

0009-2541

Publikationsdatum

21.01.2015

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Geologie, Geochemie und Petrologie

Ziele für nachhaltige Entwicklung

SDG 13 – Klimaschutzmaßnahmen, SDG 14 – Lebensraum Wasser

Elektronische Version(en)

https://doi.org/10.1016/j.chemgeo.2014.11.011 (Zugang: Offen)
https://doi.org/10.15488/839 (Zugang: Offen)