Spatter matters – distinguishing primary (eruptive) and secondary (non-eruptive) spatter deposits

Jones, T.J.; Houghton, B.F.; Llewellin, E.W.; Parcheta, C.; Höltgen, L.

Abstract

Spatter is a common pyroclastic product of hawaiian fountaining, which typically forms vent-proximal ramparts or cones. Based on textural characteristics and field relations of spatter from the 1969 Mauna Ulu eruption of Kīlauea, Hawai’i, three spatter types were identified: (1) Primary spatter deposited as spatter ramparts and isolated cones during the peak of episode 1; (2) Late-stage spatter comprising dense, small volume, vent proximal deposits, formed at the end of episode 1; (3) Secondary spatter preserved in isolated mounds around tectonic ground cracks that we interpret to have formed by the disruption of overlying lava. We propose that not all spatter deposits are evidence of primary magmatic fountaining. Rather, deposits can be “secondary” in nature and associated with lava drain-back, disruption, and subsequent ejection from tectonic cracks. Importantly, these secondary pyroclastic deposits are difficult to distinguish from primary eruptive features based on field relations and bulk clast vesicularity alone, allowing for the potential misinterpretation of eruption vents, on Earth and in remotely sensed planetary data, thereby misinforming hazard maps and probabilistic assessments. Here, we show that vesicle number density provides a statistically-robust metric by which to discriminate primary and secondary spatter, supporting accurate identification of eruptive vents.

Citation

Jones, T., Houghton, B., Llewellin, E., Parcheta, C., & Höltgen, L. (2018). Spatter matters – distinguishing primary (eruptive) and secondary (non-eruptive) spatter deposits. Scientific Reports, 8, Article 9179. https://doi.org/10.1038/s41598-018-27065-1

• Journal Article Type: Article
• Acceptance Date: May 29, 2018
• Online Publication Date: Jun 15, 2018
• Publication Date: Jun 15, 2018
• Deposit Date: Apr 10, 2018
• Publicly Available Date: Jun 15, 2018
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Article Number: 9179
• DOI: https://doi.org/10.1038/s41598-018-27065-1
• Public URL: https://durham-repository.worktribe.com/output/1329428