Controls on the expression of igneous intrusions in seismic
reflection data
reflection data
File(s)
Accepted version
Author(s)
Magee, C
Maharaj, SM
Wrona, T
Jackson, CA-L
Type
Journal Article
Abstract
The architecture of subsurface magma plumbing systems influences a variety of igneous processes, including the physiochemical evolution of magma and extrusion sites. Seismic reflection data provides a unique opportunity to image and analyze these subvolcanic systems in three dimensions and has arguably revolutionized our understanding of magma emplacement. In particular, the observation of (1) interconnected sills, (2) transgressive sill limbs, and (3) magma flow indicators in seismic data suggest that sill complexes can facilitate significant lateral (tens to hundreds of kilometers) and vertical (<5 km) magma transport. However, it is often difficult to determine the validity
of seismic interpretations of igneous features because they are rarely
drilled, and our ability to compare seismically imaged features to potential field analogues is hampered by the limited resolution of seismic data. Here we use field observations to constrain a series of novel seismic forward models that examine how different sill morphologies may be expressed in seismic data. By varying the geologic architecture (e.g., host-rock lithology and intrusion thickness) and seismic properties (e.g., frequency), the models demonstrate
that seismic amplitude variations and reflection configurations can be
used to constrain intrusion geometry. However, our results also highlight that stratigraphic reflections can interfere with reflections generated at the intrusive contacts, and may thus produce seismic artifacts that could be misinterpreted as real features. This study emphasizes the value of seismic data to understanding magmatic systems and demonstrates the role that synthetic seismic forward modeling can play in bridging the gap between seismic data and field observations.
of seismic interpretations of igneous features because they are rarely
drilled, and our ability to compare seismically imaged features to potential field analogues is hampered by the limited resolution of seismic data. Here we use field observations to constrain a series of novel seismic forward models that examine how different sill morphologies may be expressed in seismic data. By varying the geologic architecture (e.g., host-rock lithology and intrusion thickness) and seismic properties (e.g., frequency), the models demonstrate
that seismic amplitude variations and reflection configurations can be
used to constrain intrusion geometry. However, our results also highlight that stratigraphic reflections can interfere with reflections generated at the intrusive contacts, and may thus produce seismic artifacts that could be misinterpreted as real features. This study emphasizes the value of seismic data to understanding magmatic systems and demonstrates the role that synthetic seismic forward modeling can play in bridging the gap between seismic data and field observations.
Date Issued
2015-06-16
Date Acceptance
2015-05-11
Citation
Geosphere, 2015, 11 (4), pp.1-18
ISSN
1553-040X
Publisher
Geological Society of America
Start Page
1
End Page
18
Journal / Book Title
Geosphere
Volume
11
Issue
4
Copyright Statement
© 2015 The Geological Society of America. Published version can be viewed here: http://doi.org/10.1130/GES01150.1
Description
24/06/15 AAM can be deposited in Spiral subject to a 12 month embargo
Publication Status
Published
Coverage Spatial
United States