Rock-Melt Interactions in Mantle Xenoliths from Two Intraplate Settings (Tariat, Mongolia and Kilbourne Hole, New Mexico)

Authors

Gustavo Marchant Allende, Macalester CollegeFollow

Document Type

Honors Project On-Campus Access Only

Abstract

Interactions between Earth’s lithospheric mantle and migrating melts contribute to mantle heterogeneity. Mantle xenoliths from Tariat, Mongolia, and Kilbourne Hole, New Mexico, record distinct melt-rock interactions. Tariat xenoliths (equilibrated at 930 – 950 ◦C) contain a pyroxenite vein formed by prolonged equilibration with Si-rich melts. Kilbourne Hole xenoliths (1050 – 1150 ◦C) show evidence of brief basaltic melt interactions. Mineral chemical profiles near melt interfaces exhibit elevated Mg in or- thopyroxene (Mg# > 90), Ti depletion in clinopyroxene, and elevated Cr in spinel (Cr# > 23), indicating localized melt depletion. Diffusion modeling and geospeedom- etry constrain melt-rock interaction timescales, spanning decades at Kilbourne Hole and thousands of years at Tariat.

Recommended Citation

Marchant Allende, Gustavo, "Rock-Melt Interactions in Mantle Xenoliths from Two Intraplate Settings (Tariat, Mongolia and Kilbourne Hole, New Mexico)" (2025). Geology Honors Projects. 29.
https://digitalcommons.macalester.edu/geology_honors/29