Tracking Subsurface Active Weathering Processes in Serpentinite
Letter to the Editor
Date of Original Version
We conducted a novel study to capture the on-going advancement of mineral weathering within a serpentinite formation by using an integrated approach of multi-scale quantitative rock magnetic analyses and nano-resolution geochemical imaging analyses. We studied a suite of rock samples from the Coast Range Ophiolite Microbial Observatory (CROMO) in California to conduct rock magnetic analyses enabling us to determine character of Fe-bearing minerals and to predict locations of reaction boundaries among various stages of weathering. QEMSCAN® and other electron micro-imagery analyses highlighted microstructural changes in amorphous minerals, and possible changes in porosity and coincides with the iron-enrichment region. This iron enrichment indicates initiation of iron (-oxides) nucleation, resulting in extremely fine gain magnetite formation. This is a newly documented mode of magnetite production in serpentinites and enhances the application of magnetite abundance as a proxy for the degree and extent of water-rock interaction in mantle peridotite and serpentinite.
Publication Title, e.g., Journal
Geophysical Research Letters
Tominaga, Masako, Estefania Ortiz, Joshua F. Einsle, Noah F. Ryoichi Vento, Matthew O. Schrenk, Iris Buisman, Isra S. Ezad, and Dawn Cardace. "Tracking Subsurface Active Weathering Processes in Serpentinite." Geophysical Research Letters 48, 6 (2021). doi: 10.1029/2020GL088472.