Open AccessA multiaxial growth analysis of stable isotopes in the modern shell of Saxidomus gigantea : Implications for sclerochronology studies
Author(s) -
Kingston Andrew W.,
Gröcke Darren R.,
Burchell Meghan
Publication year - 2008
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2007gc001807
Subject(s) - shell (structure) , sinistral and dextral , isotope , stable isotope ratio , geology , isotope analysis , δ13c , paleontology , materials science , physics , oceanography , fault (geology) , nuclear physics , composite material
Stable‐isotope ratios of two modern Saxidomus gigantea specimens from Namu, British Columbia, are presented to show intraspecimen and interspecimen isotopic variation. Isotopic profiles ( δ 13 C shell , δ 18 O shell ) were generated along the axis of maximum growth. The profiles show that analogous seasonal variation is recorded in δ 18 O shell ; however, significant variability is recorded in δ 13 C shell . We suggest this is caused by differences in metabolic activity between individuals. Intrashell variability along a growth horizon shows good reproducibility in δ 13 C shell but significant variability in δ 18 O shell , especially at the sinistral margin. A multiaxial growth analysis generated several profiles from a single valve. Similar seasonal variations are recorded in δ 18 O shell along all axes. δ 13 C shell show significantly less covariation, possibly related to internal metabolic activity. This study highlights that δ 18 O shell profiles generated from any portion of the shell can be used to evaluate seasonal fluctuations and may be excellent to evaluate types and rates of shell growth.