Large calcium isotope fractionations by zeolite minerals from Iceland

Claire J. Nelson*, Andrew D. Jacobson, Gabriella D. Kitch, Tobias B. Weisenberger

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Zeolites are secondary tectosilicates produced during the hydrothermal alteration of basalt. The minerals serve as major sinks of calcium, which readily exchanges with calcium from surrounding groundwater. However, no studies have specifically investigated the calcium isotope geochemistry (δ44/40Ca) of zeolites. Here, we report δ44/40Ca values for zeolites from East Iceland, where the minerals form during progressive burial of the lava pile. The zeolites show a δ44/40Ca range of 1.4‰, which strongly correlates with average mineral calcium-oxygen bond lengths. As this correlation appears most consistent with equilibrium isotope partitioning, our findings point toward developing a novel geothermometer for studying low-grade basalt metamorphism. The results also have significance for using calcium isotopes to trace basalt weathering, including its role in long-term climate regulation and application in carbon capture and storage, a leading strategy for mitigating anthropogenic climate change.

Original languageEnglish (US)
Article number206
JournalCommunications Earth and Environment
Issue number1
StatePublished - Dec 2021

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Environmental Science(all)


Dive into the research topics of 'Large calcium isotope fractionations by zeolite minerals from Iceland'. Together they form a unique fingerprint.

Cite this