TY - JOUR

T1 - Efficient release of bromine by super-eruptions

AU - Waelkens, Clara M.

AU - Stix, John

AU - Monteleone, Brian

AU - Burckel, Pierre

N1 - Funding information: We thank Anita Cadoux and Kim Berlo for reference glasses, Lang Shi for assistance on the electron microprobe, and Nicole Bobrowski and two anonymous reviewers for constructive comments. This research was supported by a Geological Society of America grant (C. Waelkens), Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery and CREATE grants (J. Stix), and Institut de Physique du Globe de Paris multidisciplinary program PARI and Paris-IdF region SESAME grant 12015908 (P. Burckel). The Northeast National Ion Microprobe Facility is subsidized by U.S. National Science Foundation (NSF) facility support grant NSF-EAR-1664308. We thank Anita Cadoux and Kim Berlo for reference glasses, Lang Shi for assistance on the electron microprobe, and Nicole Bobrowski and two anonymous reviewers for constructive comments. This research was supported by a Geological Society of America grant (C. Waelkens), Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery and CREATE grants (J. Stix), and Insti-tut de Physique du Globe de Paris multidisciplinary program PARI and Paris–IdF region SESAME grant 12015908 (P. Burckel). The Northeast National Ion Microprobe Facility is subsidized by U.S. National Science Foundation (NSF) facility support grant NSF-EAR-1664308.

PY - 2021/7/30

Y1 - 2021/7/30

N2 - Bromine is a key halogen element in the quantification of volcanic volatiles, but analytical difficulties in measuring its very low abundances have prevented progress in understanding its behavior and its role in volcanic emissions. We present a new data set of bromine, chlorine, and fluorine concentrations in melt inclusions and matrix glasses for two rhyolitic super-eruptions from the Toledo and Valles calderas, New Mexico, USA. We show that before eruption, Br and Cl were efficiently partitioned from the gas-saturated magma into a separate fluid phase, and we calculate the mass of halogens in the fluid phase. We further demonstrate that syn-eruptive magma degassing was negligible during the super-eruptions, so that the main source of halogen emissions must have been the fluid phase. If the fluid phase were erupted, the large mass of Br and Cl could have severely impacted the atmospheric chemistry upon eruption.

AB - Bromine is a key halogen element in the quantification of volcanic volatiles, but analytical difficulties in measuring its very low abundances have prevented progress in understanding its behavior and its role in volcanic emissions. We present a new data set of bromine, chlorine, and fluorine concentrations in melt inclusions and matrix glasses for two rhyolitic super-eruptions from the Toledo and Valles calderas, New Mexico, USA. We show that before eruption, Br and Cl were efficiently partitioned from the gas-saturated magma into a separate fluid phase, and we calculate the mass of halogens in the fluid phase. We further demonstrate that syn-eruptive magma degassing was negligible during the super-eruptions, so that the main source of halogen emissions must have been the fluid phase. If the fluid phase were erupted, the large mass of Br and Cl could have severely impacted the atmospheric chemistry upon eruption.

UR - http://www.scopus.com/inward/record.url?scp=85120736252&partnerID=8YFLogxK

U2 - 10.1130/G49114.1

DO - 10.1130/G49114.1

M3 - Article

VL - 49

SP - 1416

EP - 1420

JO - GEOLOGY

JF - GEOLOGY

SN - 0091-7613

IS - 12

ER -