Magma Differentiation in Dynamic Mush Domains From the Perspective of Multivariate Statistics: Open- Versus Closed-System Evolution
OPEN ACCESS
Loading...
Author / Producer
Date
2024-03
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
OPEN ACCESS
Data
Abstract
Open-conduit conditions characterize several of the most hazardous and active volcanic systems of basaltic composition worldwide, persistently refilled by magmatic inputs. Eruptive products with similar bulk compositions, chemically buffered by continual mafic inputs, nevertheless exhibit heterogeneous glass compositions in response to variable magma mixing, crystallization, and differentiation processes within different parts of the plumbing system. Here, we document how multivariate statistics and magma differentiation modeling based on a large data set of glass compositions can be combined to constrain magma differentiation and plumbing system dynamics. Major and trace elements of matrix glasses erupted at Stromboli volcano (Italy) over the last 20 years provide a benchmark against which to test our integrated petrological approach. Principal component analysis, K-means cluster analysis, and kernel density estimation reveal that trace elements define a multivariate space whose eigenvectors are more readily interpretable in terms of petrological processes than major elements, leading to improved clustering solutions. Comparison between open- and closed-system differentiation models outlines that steady state magma compositions at constantly replenished and erupting magmatic systems approximate simple fractional crystallization trends, due to short magma residence times. Open-system magma evolution is associated with magma storage crystallinities that are lower than those associated with closed-system scenarios. Accordingly, open-system dynamics determine the efficient crystal-melt separation toward the top of the reservoir, where eruptible melts continuously supply the ordinary activity. Conversely, a mush-like environment constitutes the bottom of the reservoir, where poorly evolved magmas result from mixing events between mush residual melts and primitive magmas injected from deeper crustal levels.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
25 (3)
Pages / Article No.
Publisher
American Geophysical Union
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
stromboli volcano; multivariate statistics; geochemical modeling; magmatic differentiation
Organisational unit
03958 - Bachmann, Olivier / Bachmann, Olivier
Notes
Funding
197040 - Defining ‘super-eruptive’ frequencies from the Yellowstone hotspot track (SNF)