TY - JOUR
T1 - Large calcium isotope fractionations by zeolite minerals from Iceland
AU - Nelson, Claire J.
AU - Jacobson, Andrew D.
AU - Kitch, Gabriella D.
AU - Weisenberger, Tobias B.
N1 - Funding Information:
Special thanks to M. Gasser, C. Feucht, and H. Dijkstra for help with field collection, M. Ankney and M. Wood for help with laboratory work, and F. Albarède and M.G. Andrews for insightful discussions. Three reviewers provided thoughtful feedback that improved the manuscript. This work was supported by NSF-EAR 1613359 awarded to A.D.J.
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - 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.
AB - 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.
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U2 - 10.1038/s43247-021-00274-9
DO - 10.1038/s43247-021-00274-9
M3 - Article
AN - SCOPUS:85125776141
SN - 2662-4435
VL - 2
JO - Communications Earth and Environment
JF - Communications Earth and Environment
IS - 1
M1 - 206
ER -
