Open AccessLi partitioning in the benthic foraminifera A mphistegina lessonii
Author(s) -
Langer Gerald,
Sadekov Aleksey,
Thoms Silke,
Mewes Antje,
Nehrke Gernot,
Greaves Mervyn,
Misra Sambuddha,
Bijma Jelle,
Elderfield Henry
Publication year - 2015
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1002/2015gc006134
Subject(s) - calcite , seawater , foraminifera , divalent , benthic zone , geology , alkali metal , mineralogy , chemistry , oceanography , organic chemistry
Abstract The shallow water benthic foraminifer Amphistegina lessonii was grown in seawater of variable Li and Ca concentration and shell Li/Ca was determined by means of LA‐ICPMS. Shell Li/Ca is positively correlated to seawater Li/Ca only when the Li concentration of seawater is changed. If the seawater Ca concentration is changed, shell Li/Ca remains constant. This indicates that Li does not compete with Ca for incorporation in the shell of A. lessonii . A recently proposed calcification model can be applied to divalent cations (e.g., Mg and Sr), which compete for binding sites of ion transporters and positions in the calcite lattice. By contrast, the transport pathway of monovalent cations such as Li is probably diffusion based (e.g., ion‐channels), and monovalent cations do not compete with Ca for a position in the calcite lattice. Here we present a new model for Li partitioning into foraminiferal calcite which predicts our experimental results and should also be applicable to other alkali metals.