Testing the Limits of Provenance Analysis from Basaltic Fluvial Sediment Near Sandvatn, Iceland, as a Mars Analog

Authors

• Audrey R. Putnam, Rice University
• Kirsten L. Siebach, Rice University
• Michael T. Thorpe, NASA Goddard Space Flight Center
• Valerie M. Tu, Texas State University (TXST)/Amentum-JETSII at NASA JSC
• Elizabeth B. Rampe, Purdue University
• Candice C. Bedford, NASA Johnson Space Center
• Gelu Costin, Rice University
• Joseph J. Tamborski, Old Dominion UniversityFollow

ORCID

0000-0003-2422-3252 (Tamborski)

Document Type

Article

Publication Date

2026

DOI

10.1029/2025JE009400

Publication Title

Journal of Geophysical Research - Planets

Volume

131

Issue

4

Pages

e2025JE009400

Abstract

Detrital sediments that accumulate downstream and are preserved in sedimentary rocks can allow characterization of geologic formations that are inaccessible for spatial or temporal reasons. However, mixing, sorting, and alteration of sediment during transport may complicate reconstruction of protolith characteristics. We test the preservation of three key provenance signals in coarse fluvial sand at a Mars analog watershed in Iceland to determine whether detrital sediments capture (a) watershed magmatic chemical variation, (b) textural indicators of lava-water interaction during eruption and cooling, and (c) hydrothermal alteration. Specifically, we tested whether diagnostic variations in rock mineralogy, chemistry, and texture can be recovered in the bulk mineralogy and chemistry of sand-sized sediments. In first-order basaltic fluvial sediments transported < 10 km, sediment sorting segregated grains with distinct inherited cooling textures and phenocrysts, and rendered some altered materials undetectable in bulk measurements of sand. This sorting also obscured signals of magmatic variability across the watershed and reduced the range of recorded lava cooling rates. The input of exogenous tephra to the Sandvatn watershed could only be distinguished in depositional environments with minimal active deposition or erosion and was most evident in reworked lakeshore deposits far from the delta. Bulk chemistry and mineralogy recorded different aspects of sediment sorting at Sandvatn, highlighting that integrating paired chemical and mineralogic data is key to disentangling the records of provenance composition and texture from sorted volcanic sediment.

Rights

© 2026. The Authors.

This is an open access article under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Data Availability

Article states: "The data collected and used in this study are shared in a Zenodo repository (Putnam et al., 2026)."

Original Publication Citation

Putnam, A. R., Siebach, K. L., Thorpe, M. T., Tu, V. M., Rampe, E. B., Bedford, C. C., Costin, G., & Tamborski, J. J. (2026). Testing the limits of provenance analysis from basaltic fluvial sediment near Sandvatn, Iceland, as a Mars analog. Journal of Geophysical Research - Planets, 131(4), Article e2025JE009400. https://doi.org/10.1029/2025JE009400

Repository Citation

Putnam, Audrey R.; Siebach, Kirsten L.; Thorpe, Michael T.; Tu, Valerie M.; Rampe, Elizabeth B.; Bedford, Candice C.; Costin, Gelu; and Tamborski, Joseph J., "Testing the Limits of Provenance Analysis from Basaltic Fluvial Sediment Near Sandvatn, Iceland, as a Mars Analog" (2026). OES Faculty Publications. 574.
https://digitalcommons.odu.edu/oeas_fac_pubs/574