Rapid assembly of high-Mg andesites and dacites by magma mixing at a continental arc stratovolcano
Affiliation
Research Institute of Earthquake and Volcano Geology, JapanNational Museum of Nature and Science, Japan
University of Derby
University of Leeds
Victoria University of Wellington
Issue Date
2020-06-25
Metadata
Show full item recordAbstract
Studies of pre-eruptive processes at active volcanoes require precise petrochronological constraints if they are to contribute to hazard assessment during future eruption events. We present petrological and geochemical data, and orthopyroxene diffusion timescales for samples from late Pleistocene high-Mg andesite dacite lavas (Mg#53–69) at Ruapehu volcano, New Zealand, as a case study of rapid magma genesis and eruption at a continental arc stratovolcano. Assembly of Ruapehu high-Mg magmas involved the mixing of primitive magmas plus entrained mantle equilibrated olivines with mid-crustal felsic mush bodies, yielding hybridized magmas with ubiquitous pyroxene reverse-zoning patterns. Orthopyroxene Fe-Mg interdiffusion timescales linked to quantitative crystal orientation data show that most lavas erupted <10 days after resumption of crystal growth following magma mixing events. The eruption of lavas within days of mixing events implies that pre-eruptive warnings may be correspondingly short.Citation
Chamberlain, K. (2020). 'Rapid assembly of high-Mg andesites and dacites by magma mixing at a continental arc stratovolcano'. Geology, pp. 1-5.Publisher
The Geological Society of AmericaJournal
GeologyDOI
10.1130/G47614.1Additional Links
https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G47614.1/587599/Rapid-assembly-of-high-Mg-andesites-and-dacites-byType
ArticleLanguage
enISSN
0091-7613EISSN
1943-2682ae974a485f413a2113503eed53cd6c53
10.1130/G47614.1