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Title: Efficient release of bromine by super-eruptions
Abstract 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.  more » « less
Award ID(s):
1664308
NSF-PAR ID:
10312559
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
Geology
Volume:
49
Issue:
12
ISSN:
0091-7613
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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