A recent snapshot of Koma Kulshan's (Mt. Baker's) magma storage system
Research Mentor(s)
Susan DeBari
Description
Combining mineral chemistry from zoned crystals with thermobarometry, temperature and pressure calculations, and thermodynamic modeling is a powerful way to provide constraints on magmatic processes beneath an active volcano. Numerous populations of crystals in Koma Kulshan’s (Mount Baker’s) youngest (9.8 ka) lava flow represent four compositionally different magmas involved in the eruption. These magmas are identified by textural observations and the chemistry of crystals in the flow. The host lava flow (Sulphur Creek) is composed of two segments a basalt at the toe and a basaltic andesite flow towards the source. The basaltic segment carries crystals from the B3, D1, and B2 magmas and the basaltic andesite carries crystals from the BA3, D1, and B2 magmas. These crystals coupled with observed mixing textures in this basaltic andesite part of the lava flow, suggest mixing of the B3 and D1 magmas to generate a large mush-like BA3 magma. Thermobarometry and thermodynamic modelling place the BA3 magma at 3.4 km, 10 km, and 18 km below Koma Kulshan. The D1 and B2 magmas have been previously identified in lavas flows that span the last 100 ka of Koma Kulshan’s eruptive history, suggestive of the presence of long-lived magmas beneath the volcano.
Document Type
Event
Start Date
May 2022
End Date
May 2022
Location
SMATE Library (Bellingham, Wash.)
Department
Geology
Genre/Form
student projects; posters
Type
Image
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.
Language
English
Format
application/pdf
A recent snapshot of Koma Kulshan's (Mt. Baker's) magma storage system
SMATE Library (Bellingham, Wash.)
Combining mineral chemistry from zoned crystals with thermobarometry, temperature and pressure calculations, and thermodynamic modeling is a powerful way to provide constraints on magmatic processes beneath an active volcano. Numerous populations of crystals in Koma Kulshan’s (Mount Baker’s) youngest (9.8 ka) lava flow represent four compositionally different magmas involved in the eruption. These magmas are identified by textural observations and the chemistry of crystals in the flow. The host lava flow (Sulphur Creek) is composed of two segments a basalt at the toe and a basaltic andesite flow towards the source. The basaltic segment carries crystals from the B3, D1, and B2 magmas and the basaltic andesite carries crystals from the BA3, D1, and B2 magmas. These crystals coupled with observed mixing textures in this basaltic andesite part of the lava flow, suggest mixing of the B3 and D1 magmas to generate a large mush-like BA3 magma. Thermobarometry and thermodynamic modelling place the BA3 magma at 3.4 km, 10 km, and 18 km below Koma Kulshan. The D1 and B2 magmas have been previously identified in lavas flows that span the last 100 ka of Koma Kulshan’s eruptive history, suggestive of the presence of long-lived magmas beneath the volcano.
