Bridging the gap: 40Ar/39Ar dating of volcanic eruptions from the ‘Age of Discovery’

Preece, Katie; Mark, Darren F.; Barclay, Jenni; Cohen, Benjamin E.; Chamberlain, Katy J.; Jowitt, Claire; Vye-Brown, Charlotte; Brown, Richard J.; Hamilton, Scott

Abstract

Many volcanoes worldwide still have poorly resolved eruption histories, with the date of the last eruption often undetermined. One such example is Ascension Island, where the timing of the last eruption, and consequently, the activity status of the volcano, is unclear. Here, we use the 40Ar/39Ar dating technique to resolve ages of the three youngest lava flows on the island, which are hawaiites and mugearite with 1.5 – 1.9 wt% K2O. In dating these lavas, we provide the first evidence of Holocene volcanic activity on Ascension (0.51 ± 0.18 ka; 0.55 ± 0.12 ka; 1.64 ± 0.37 ka), determining that it should be classed as an active volcanic system. In addition, we demonstrate that the 40Ar/39Ar method can reproducibly date mafic lava flows younger than 1 ka, decreasing the gap between recorded history and geological dating. These results offer new prospects for determining patterns of late-Holocene volcanic activity; critical for accurate volcanic hazard assessment.

Citation

Preece, K., Mark, D. F., Barclay, J., Cohen, B. E., Chamberlain, K. J., Jowitt, C., …Hamilton, S. (2018). Bridging the gap: 40Ar/39Ar dating of volcanic eruptions from the ‘Age of Discovery’. Geology, 46(12), 1035-1038. https://doi.org/10.1130/g45415.1

• Journal Article Type: Article
• Acceptance Date: Oct 8, 2018
• Online Publication Date: Nov 9, 2018
• Publication Date: Dec 1, 2018
• Deposit Date: Nov 27, 2018
• Publicly Available Date: Nov 9, 2019
• Journal: Geology
• Print ISSN: 0091-7613
• Electronic ISSN: 1943-2682
• Publisher: Geological Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 46
• Issue: 12
• Pages: 1035-1038
• DOI: https://doi.org/10.1130/g45415.1
• Public URL: https://durham-repository.worktribe.com/output/1308475