Mesocrystalline Architecture in Hyaline Foraminifer Shells Indicates a Non-Classical Crystallisation Pathway

Author(s)

A. I. Arns, D. Evans, R. Schiebel, L. Fink, M. Mezger, E. Alig, J. Linckens, K. P. Jochum, M. U. Schmidt, A. Jantschke, G. H. Haug

Abstract

Calcareous foraminifer shells (tests) represent one of the most important archives for paleoenvironmental and paleoclimatic reconstruction. To develop a mechanistic understanding of the relationship between environmental parameters and proxy signals, knowledge of the fundamental processes operating during foraminiferal biomineralization is essential. Here, we apply microscopic and diffraction-based methods to address the crystallographic and hierarchical structure of the test wall of different hyaline foraminifer species. Our results show that the tests are constructed from micrometer-scale oriented mesocrystals built of nanometer-scale entities. Based on these observations, we propose a mechanistic extension to the biomineralization model for hyaline foraminifers, centered on the formation and assembly of units of metastable carbonate phases to the final mesocrystal via a non-classical particle attachment process, possibly facilitated by organic matter. This implies the presence of metastable precursors such as vaterite or amorphous calcium carbonate, along with phase transitions to calcite, which is relevant for the mechanistic understanding of proxy incorporation in the hyaline foraminifers.

Organisation(s)

Dynamics of Condensed Systems

External organisation(s)

Max-Planck-Institut für Chemie (Otto-Hahn-Institut), Johann Wolfgang Goethe-Universität Frankfurt am Main, Johannes Gutenberg-Universität Mainz, Eidgenössische Technische Hochschule Zürich

Journal

Geochemistry, Geophysics, Geosystems

Volume

23

No. of pages

18

ISSN

1525-2027

DOI

https://doi.org/10.1029/2022GC010445

Publication date

06-2022

Peer reviewed

Yes

Austrian Fields of Science 2012

105102 General geophysics, 105105 Geochemistry

Keywords

ASJC Scopus subject areas

Geochemistry and Petrology, Geophysics

Portal url

https://ucrisportal.univie.ac.at/en/publications/mesocrystalline-architecture-in-hyaline-foraminifer-shells-indicates-a-nonclassical-crystallisation-pathway(cd41a279-ba4f-45aa-9ff8-ca073a8c2874).html