Transport and deposition of an olivine crystal cargo in the Moinui Flow, Hawai’i – [publication]

Lavas are commonly erupted carrying cargos of crystals that formed somewhere in the plumbing system beneath the volcano, and these crystal cargos can give useful information about the passage of magma to the surface. The Moinui lava flow on Mauna Loa, Hawaiʻi, is one such example. The lava contains two populations of olivine crystals: clusters of touching grains, and an unusual population of dendritic crystals that we have concluded formed during the eruption itself. Subsequent to eruption, lava flowed over 30 km to the sea in a series of interconnected lobes and tubes. The internal structure and geometry of the flow shows that it developed as a complex series of interconnected tube-fed inflating lobes, whose architecture depended mostly on the topography of the substrate. The distribution of the olivine populations in a set of samples collected along the flow path gives us clues as to how long this took, and what the internal processes were within the lava. Investigation of the geometry of the olivine clusters using 3D X-ray microtomography provides some important new insights. The nature of the olivine clusters has broader relevance to an ongoing debate among igneous petrologists about how crystals nucleate and grow from magmas

This new open access publication is available at https://doi.org/10.30909/vol.07.01.247272.

Barnes, S. J., Thordarson, T., Hill, R. E. T., Perring, C. S., Dowling, S. E. & Godel, B., 2024. The Moinui Flow on Mauna Loa:  transport and deposition of an olivine crystal cargo in a compound basaltic lava flow. Volcanica, v.7