Fluids and Magmas National Meeting Summary Report

Fluids and Magmas TWG Summary
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Fluids and Magmas: Report on Thursday's Discussion

• How do Magmas & Fluids control rheological properties of the lithosphere/asthenosphere (Hirth Model) vs localize deformation (Buck model)?
• How do Magmas & Fluids relate to “Red” ?
• What is the pace of magma production and continental growth?
• What is the lithospheric and magmatic response to mantle drips and SSC ?
• What is the deep plumbing system of a volcano?

The Need for Exchange and Cross-Education among Geophysicists and Petrologists, Mineral Physicists, Geologists, Geochemists, Geochronologiss

The Importance of Maintaining and Growing Igneous Rock and Xenoliths Databases

Integrative Theoretical Institutes

1. Mantle Drips and the Dynamic Response

2. The Pace of Magma Production & Continental Growth

3. The Volcanic System: from the Surface to the Mantle

Session Overview

1. Open discussion of science results

2. Future science goals - what do we hope to accomplish from EarthScope?

TWG Concepts

1. Provide forum for broad dissemination of results in a variety of forms

- Blog, bibliography, figure distribution, more
- Tools are one the way...

2. Facilitate community involvement and collaboration
3. Promote science being produced from EarthScope on a wide range of topics

Today's Charge to the TWGs

• (1) Identify key elements within discipline that constitute frontier problems and that are vital for the science.


• (2) Identify how to maximize the scientific output from EarthScope. What kinds of integrative activities might your working group develop to spur discussion? For example, one group is compiling members' different strain rate models to discuss at the meetings.


• (3) With USArray moving east, what are the major scientific targets to consider?


• (4) Identify key, multidisciplinary topics to be investigated at a Workshop that will be held in the fall of 2009. The Science Plan will emerge from this workshop.


• (5) Identify a key topic in your own field that warrants a broad, thematic workshop. For example, one workshop idea that has come forward is Transient Strain and Episodic Slip.

Fluids, and Magmas (?)

NSF Solicitation (and F&M TWG web page) - Primary Science Questions

• What effect does tectonic deformation have on fluid flow in the crust?
• What is the role of hotspots in evolution of the continents?
• How does tectonic rate (convergence, extension, mangtle upwelling) affect magma production?
• Where does melting in the lithosphere occur and what controls magma migration, accumulation, and residence time?
• What is the relation between magma movement, surface deformation, and volcanic eruption
• Over what temporal and spatial scales do earthquake deformation and volcanic eruptions couple?
• What controls eruption style?
• What are the predictive signs of imminent volcanic eruption? What are the structural, rheological, and chemical controls on fluid flow in the crust?

2002 Scientific Targets Workshop Report

1. Magma genesis

2. Magma transport

3. Volcanic eruption, prediction, and hazard mitigation

Fluids and Magmas

2002 Scientific Targets Workshop Report

1. Magma genesis

• How do tectonic rates (e.g., convergence, extension, or mantle upwelling rates) affect magma production rates?
• Where in the mantle does melting occur, and what path does the melt take through the upper mantle and into the crust?
• What combination of seismic parameters can resolve mantle temperature, melt, and fluid heterogeneities?
• What volume of the North American continent was created by recent (since when?) magmatism? During the Cenozoic? At various 0me intervals in the past? What is the pulse of continental growth?

2. Magma Transport

• What controls the depth of magma accumulation in the upper crust, and why do some volcanoes accumulate magma quasi‐statically and others episodically?
• What controls the shape and size of magma reservoirs and conduits?
• How is magma transport related to tectonic sedng, magma composition, magma supply rate, lithospheric structures, and/or local stress regime?
• How do different plumbing structures constrain the dynamics of magma flow, deformation, eruption dynamics, and hazard potential?
• What is the residence time of magma in the crust?
• Can rising magma be detected before it reaches the brifle‐ductiletransition as a means to probe condi0ons in the deeper crust?

3. Volcanic eruption, prediction, and hazard mitigation

• What is the relationship among deep magma movement, surface deformation, and volcanic eruption?
• Over what temporal and spatial scales do earthquake deforma0on and volcanic eruptions couple?
• Are there telltale signs in deformation data that can be used to infer whether magma moving toward the surface will reach the surface, and if it does, how explosive the eruption will be?
• What is the effect of tectonic sedng, magma composition, lithospheric structure, and stress on eruption style?

Alternative topics to consider

Role of fluids in controlling or modulating deforma0on at a variety of spatial and temporal scales:

• Volatile, fluid, and melt content will control rheology of sublithospheric and lithospheric mantle (the Hirth model)
• High fluid and melt content can enable localized extensional deformation in the lithospheric mantle (the Buck model)
• Fluid content and fluid pressure can significantly alter the temporal and spatial distribution of seismic and aseismic slip on faults

Role of non‐magmatic fluids in crust:

• deep crustal fluid flow and degassing;
• pressure‐temperature‐driven metamorphism and metasoma0sm;
• fluid coupling to stress/strain;
• deep basin hydrogeologic processes;
• how crustal rheology contributes to chemical and mass transport in the crust;
• how crustal strength and its deformation mechanisms contribute to secondary reaction and transport;
• how to scale laboratory deformation experiments to the crustal scale to define the frequency of episodic fluid transport.

Charge from the NSF

• It has been 8 years since Snowbird Workshop: Need an Updated Plan

• -> Identify high-priority, new, and emerging areas of scientific exploration for the EarthScope Program over the next 5-10 years


• -> Transformative, interdisciplinary science and include some areas that may be speculative today, but with a high potential return.


• -> The plan will not make specific budgetary recommendations, but may identify areas where additional resources could be beneficial.


• -> Inform future NSF decisions on the EarthScope Program.


• -> To expand and enhance the already vibrant EarthScope community.