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Determining the long-term behavior of intraplate volcanic fields: An integrated study of physical volcanology, tectonics and hazard assessment. Amanda R Hintz SUNY University at Buffalo May 29, 2009. Overview. Overview Introduction and Significance Background and Geology - PowerPoint PPT Presentation
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Amanda R Hintz
SUNY University at Buffalo
May 29, 2009
Long-term volcanic field behavior
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Provide new insights to the overall nature of volcanic fields
Improve the understanding of processes
governing the evolution of volcanic fields and long-term hazard issues
Image Credit: http://earthobservatory.nasa.gov/IOTD/view.php?id=8650
5 km
Volcanic field variability
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
What are the processes that ultimately control the timing, distribution, eruptive behavior of volcanic fields? Present state of knowledge
There is a need to characterize these fields’ activity and behavior to properly advance our understanding of basaltic volcanism and potential hazards Image Credit: Priest et al. (2001)
Volcanic fields are the result of a complex relationship between tectonics and magma influx
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
The Lunar Crater volcanic field (LCVF) may represent an intermediate volcanic field
Work will focus on characterizing the field in terms of its long-term time-volume behavior and identifying patterns between the LCVF and other volcanic fields
Regional geology and structure
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Image Credit: Foland and Bergman (1992)
Image Credit: Crowe et al. (1986)
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Image Credit: Smith et al. (2002)
5 km
Image Credit: http://earthweb.ess.washington.edu/EPIC/Collections/Dohrenw
end/
Eruptive History
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Geochemistry
Image Credit: Yogodzinski et al. (1996)
Reveille Range et al.
Image Credit: Dickson (1995)
LCVF
RationaleDivisions
Physical volcanology, scalesStructural and topographic
relationshipsVolumetricsTime-volume behaviorHazard assessment
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Objective : Make determinations about eruptive styles and behaviors based on physical observations to elucidate a potential correlation between volcanic fields
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Lunar Crater Maar
Observations and measurements of;Lava flowsPyroclastic conesPhenocryst, xenolith and lithic
assemblagesFeeder dike length scales
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Mantle xenolith from Easy Chair Maar
Scoria outcrop near Easy Chair Crater
Working with existing maps
Separation and definition of units
ClarificationVolcanic eventRaftsStratigraphic
relationships
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Image Credit: Modified from Snyder et al. (1972) and Dickson (1995)
Image Credit: Dohrenwend et al. (1987)
Geomorphic relationshipsBurial by
sedimentsFormation of
desert pavement on lava flows
Erosion and weathering
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Examples of desert pavement formation. Top: better formed desert pavement on older lava flow. Bottom: desert pavement is not well formed on younger flow
Vent and fault patternsAlignmentsIntersectionsEn echelon
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Image Credit: Dickson (1995)
Objective: To use the volcano-tectonic interactions in the LCVF to help distinguish the field’s underlying controls
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Reveille Range Dike-fault interactionsNear surface dike morphology,
i.e. shallow plumbingTopographic relationships
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Image Credit: http://img206.imageshack.us/img206/8048/differencexrayis9.jpg
Image Credit: http://www.landscapemodeling.org/html/ch2/images/2.51.png
Image Credit: http://populararchitecture.com/images/560/para_03.jpg
Based on;Topographic and
geologic mapsDEMs and other ‘xyz’
data availableField observations
Model
Objective: To delineate the eruptive history and time-volume relationships at LCVF to determine the relationship fundamental controls on volcanism in volcanic fields
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Image Credit: Valentine and Perry (2007)
Image Credit: Valentine and Perry (2006)
Volume calculations and feeder dike length scales will be used to estimate the ratio of tectonic to magmatic control
Time-volume behavior is a first order approximation on the long-term behavior of volcanic fields
Individual fields should also be assessed with a probabilistic approach
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Resources on handMapping, computers, software,
field equipmentNeeded resources
Potential software for volume model
Additional radiometric dating
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Image Credit: Greg Valentine (2008)
Potential ProblemsUnable to work out eruptive historyUnable to create volume modelLCVF does not show a correlation with the
time-volume behavior hypothesized
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline Alternatives
Calculate by hand Use area (?)
Limitations Exposures Software expertise
Effects on interpretations and conclusions
Large errors Erroneous hazard
analysis
Image Credit: NASA
Support of hypothesisLCVF shows characteristics of both
magmatically and tectonically controlled volcanic field
ProductsModel to evaluate interlocking and
overlapping scoria cone and lava flow volumes
Detailed mapsVolcanic field database
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
ImpactsBroadening the understanding of
volcanic field behavior Increasing the fundamental
knowledge of basaltic volcanism through better models of the timing and distribution of eruptions within volcanic fields
Potential applications to determining links between monogenetic and polygenetic volcanism
Providing the volcanological community with a case study of young volcanism and its potential eroded analogs
Hazard analysis
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
Overview Introduction
and Significance
Background and Geology
Methods and Analysis
Resources Limitations Implications
Results Timeline
