EarthScope Synthesis Workshop
Life and Death of a Craton: A 4D EarthScope perspective on the role of the Wyoming Craton in the evolution of North America
Deep Probe-SAREX Seismic Cross Section of the Wyoming Province
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Provenance: Figure Modified from Gorman (2002) by Paul Mueller, Univ. of Florida
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Workshop Program
Download the
Program and Abstracts (Acrobat (PDF) 9.1MB Feb22 19), and all the presentations can be downloaded from the links in the program below, but note that many of these files are REALLY BIG so be patient.
January 10 (Thursday)
Travel day; Check in at Lewis and Clark Hotel; Dinner 7:00 PM (meet in hotel lobby at 6:45 for shuttle to restaurant, Open Range (Main Street); Introductions; Overview; Logistics; Goals and Outcomes
January 11 (Friday) Montana State University
Daily Theme: What do we know? What have we learned about the composition, architecture and evolution of the crust/mantle system as a result of EarthScope science in (under) the Wyoming Craton?
[12 minute talks, 5-6 slides/presentation; 3 minute discussion: What "big" questions are addressed? What are the key findings and their significance? Next steps towards an integrated understanding of the North American continent?]
8:00 Breakfast service SUB 233 (Student Union); Network, make a new friend!
Overview and Context
8:30 Dave Mogk: Welcome, logistics; Context and Overview (review of 2005 EarthScope in Northern Rockies workshop) (PowerPoint 2007 (.pptx) 4.9MB Feb22 19); workshop goals and anticipated outcomes
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8:45
Suzan van der Lee, Gene Humphreys, Heather Ford:
Results of the EarthScope 4-D Evolution of North America workshop (PowerPoint 2007 (.pptx) 16MB Feb22 19): The challenges of connecting surface geology to EarthScope-resolved features.
Crustal Genesis (Archean petrogenesis, tectonics [plate or not]....)
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9:00
Paul Mueller—]
The Wyoming Province: A Unique Archean Craton (PowerPoint 2007 (.pptx) 4.5MB Feb22 19)
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9:15
Dave Mogk—
TTGs We Have Known and Loved: 1.5 Ga of Growth and Recycling of Archean Continental Crust in the Northern Wyoming Craton (NWC) (PowerPoint 2007 (.pptx) 4.7MB Feb22 19)
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9:30
Carol Frost—
The Archean geologic history of the southern Wyoming Province: a focus on the extent of ancient crust and time of cratonization. (PowerPoint 2007 (.pptx) 17.6MB Feb22 19)
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9:45
Darrell Henry—
Archean Metamorphic history of the northern Wyoming Province (NWP); implications for Precambrian plate tectonics, level of exposure across the NWP vs. metamorphic grade. (PowerPoint 25.3MB Feb22 19)
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10:00
David Bowen—
The View from (of) the Top: Considerations of the Phanerozoic Stratigraphic Cover on the Wyoming Craton (PowerPoint 2007 (.pptx) 116.3MB Feb22 19)
10:15 BREAK
Precambrian Crustal Evolution (assembly, reassembly, reworking, mobilization of the Wyoming Craton; Late Archean through Paleoproterozoic)
10:30
Kevin Chamberlain—
Some Key Observations Pertinent to the Formation and Stabilization of the Wyoming Province (Acrobat (PDF) 16.2MB Feb22 19)
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10:45
Jen Gifford—
Lessons Learned from the Great Falls Tectonic Zone, Medicine Hat-Wyoming Suture: Crustal xenoliths and the Little Rocky Mountains (PowerPoint 2007 (.pptx) 20.3MB Feb22 19)
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11:00
Julie Baldwin— Paleoproterozoic metasupracrustal suites on the NW flank of the Wyoming Province: insights into an evolving continent (PowerPoint 2007 (.pptx) 86.7MB Feb22 19)
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11:15
Jeff Vervoort—
Neoarchean and Paleoproterozoic crystalline basement rocks of the Clearwater and Priest River complexes: Constraints on the formation of western Laurentia (PowerPoint 2007 (.pptx) 41.9MB Feb22 19)
11:30
Ryan Wilhelmi—
Nothing Quiet on the Western Front: Late Archean to Neoproterozoic Evolution of West-Central Laurentia (PowerPoint 2007 (.pptx) 33.4MB Feb25 19)
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11:45
Kevin Mahan –
Deep crustal structure, processes, and properties from xenoliths, basement exposures, and seismic observations in the northern Rocky Mountain region (PowerPoint 2007 (.pptx) 41.1MB Feb22 19)
12:00 Lunch—Catered, Room 230 SUB
Post-Cratonization Geologic History/Contemporary Structure
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1:00
Dave Mogk/Paul Mueller/Carol Frost:
Some Reflections on the Mesoproterozoic Belt- Purcell Basin (PowerPoint 2007 (.pptx) 3.8MB Feb22 19)
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1:15
Tom Kalakay—From Contraction to Extension: Tectonomagmatic Architecture of the Sevier Orogenic Wedge of Western Montana (PowerPoint 2007 (.pptx) 41.8MB Feb22 19)
What's Up With the Mantle?
1:30 General Discussion (led by Paul Bedrosian): What can we learn from magnetotellurics about deep crustal structure, shear zones, hydration of the crust and controls on crustal strength
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1:45
David Snyder: Weakening Cratons by Metasomatism: Conductivity Maps the Alteration (PowerPoint 2007 (.pptx) 9.9MB Feb22 19)
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2:00
Heather Bedle :
Synthesis of regional-scale geophysical, geochemical, and thermal models of the crust and upper mantle beneath the Wyoming craton (PowerPoint 2007 (.pptx) 10.4MB Feb22 19)
2:15
Katie Cooper:
The Making and Breaking of Cratons (Acrobat (PDF) 1.3MB Feb22 19)
2:30 Break
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2:45
Suzan Van Der Lee:
The Wyoming Craton is no Longer a Craton (PowerPoint 2007 (.pptx) 2.8MB Feb22 19)
3:00
Gene Humphreys:
Laramide-age growth of the Wyoming Craton by ocean plateau under-accretion (Acrobat (PDF) 35.5MB Feb22 19)
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3:15
Vera Schulte-Pelkum:
Deformation and Structural Evolution of the Deep Crust and Lithosphere from EarthScope Seismic Data and Geological Ground Truth (PowerPoint 2007 (.pptx) 19.6MB Feb22 19)
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3:30
Heather Ford:
Imaging the mantle structure of cratons: Implications for the formation and modification of the Wyoming lithosphere (PowerPoint 2007 (.pptx) 82.5MB Feb22 19)
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3:45
Ray Russo:
Results from the IDOR (Idaho-Oregon) Passive Seismic Experiment) (PowerPoint 2007 (.pptx) 152.7MB Feb22 19)
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4:00
Bob Detrick-- The Transportable Array—A Unique capability for the Earth Sciences Community (PowerPoint 2007 (.pptx) 17.6MB Feb22 19)
4:15 - 5:30 General Discussion and Reflections
Suggested Discussion Questions: [We will not have time to address all these questions. But, they can be possible topics for focused writing in the rest of the workshop and beyond. These questions derive from earlier workshop reports, EarthScope Science plans, and other communications.]
- When and how are cratons formed? What are the chemical and physical properties of cratons? How are craton-keel systems established and what are the geodynamic implications of their survival?
- What are the geochemical/geochronological/geophysical components that are unique (or intrinsic) to the Wyoming Craton, and how do these compare with cratons of the world (Superior, Slave, Kaapvaal, Pilbara....)?
- Some cratons have Hadean roots and others not. Wyoming does—is there any effect on subsequent history?
- When and how has the Wyoming Craton been modified/reactivated chemically and physically?
- What is the role of the Wyoming Craton in the assembly of Laurentia? Why do some Archean cratons resist Proterozoic reactivation, and some don't? What does it mean if the GFTZ and THO are the same age? How does Wyoming fit in the overall evolution of the "United Plates of America"?
- Is the Wyoming Craton being destroyed—tectonic erosion, foundering, delamination? What is the impact of the Yellowstone "hot spot" and "who" will win the battle between the craton and the hot spot?
- The Belt Basin--what is the implication of the non-Laurentian zircons in the belt? Where did all the sediment come from that fills the belt basin? How did the craton survive such large-scale extension (20 km of sediment)?
- Phanerozoic events: how has the margin of the Wyoming Craton been modified by the Mesozoic accreted terranes? Why did Laramide-style deformation penetrate the craton, while Sevier-style deformation was relatively limited? What about Eocene, Miocene, and Quaternary (Basin and Range) extension?
- Significance of Eocene alkalic volcanism in the Montana alkali province/GFTZ.
6:00 Dinner Downtown (TBD); continued discussion; networking...
January 12 (Saturday) Montana State University Student Union Building Room 230
Daily Theme: The "work" day of the workshop. Addressing the "big questions" of integrated EarthScope Science and Education
Small group discussions in break out groups; report out to whole group.
Outcome: detailed outline of a) Big questions, b) Evidence from EarthScope science [maps, figures, graphs, datasets, data-products such as tomograms....], c) Key findings and interpretations. Group work will be recorded in Google Docs for future development.
8:00 Breakfast service SUB 230; Networking
8:30-9:30 Whole group discussion
a) Big ideas from yesterday's presentations to be added to the list of discussion topics from the end of Friday's session.
b) Big questions identified in EarthScope Science Plan AND from 2005 EarthScope in the Northern Rockies workshop (how well did we do in the past decade in identifying and addressing these questions)?
c) Charge to working/writing groups
Working Groups I—Organized by Disciplinary approaches
[Outcomes: Record discussion topics in the Google Drive as a detailed outline of a) Highest priority research topics; b) Major contributions; c) Major results and interpretations; and d) References. Note: at 10:30 some participants may want to migrate to another session, or emissaries may be sent from one group to another to integrate information]
1. Archean/Paleoproterozoic crustal evolution (geochemistry, geochronology, isotopic emphasis) [Mueller, Frost, Mogk, Vervoort, Gifford]
2. Precambrian to Phanerozoic geology, petrology, tectonics, structural geology, basin formation, magmatism [Baldwin, Chamberlain, Henry, Karlstrom, Kalakay, Mahan, Bowen]
3. Lithospheric/mantle structure [Bedle, Cooper, Russo, Van der Lee, Schulte-Pelkum, Ford, Humphreys, Detrick, Bedrosian]
9:30-11:30 Small Group Discussions: a) Geochemistry/geochronology/isotopic tracers; b) structural geology/tectonics/petrology; c) Geophysics. (Record key discussion points on Google Docs); Take a break as needed. (Rooms 232, 230 available for break outs).
11:30-12:15 Report Outs from Discussion Groups (15 minute overviews)
12:15-1:15 LUNCH
1:15-1:45 Whole Group Discussion—Cross-cutting and Integrative Science
Suggested topics from earlier workshops/literature. Group will help refine these topics and self-select for participation. [Refine or add to topics below. Then form small working/writing groups to explore topics of highest importance and interest].
What does EarthScope science tell us about these suggested topics:
a. Archean tectonics/geodynamics; processes, pathways, rates, heat production, crust formation/extraction, global geochemical recycling back to the mantle, magmatism......
b. Paleoproterozoic mobile belts—what is the nature/relationship of GFTZ, THO, southern accreted terranes, supercontinent cycles......
c. Cratonization and geodynamics—when and how did the tectosphere form? How does mantle structure/dynamics impact crustal structures, epeirogeny vs. orogeny, basin formation (how continental lithosphere accommodated the immense thickness of Belt basin sedimentation), modern Laramide, Sevier, Basin and Range structures...?
d. The nature of the boundary between the western edge of Precambrian North America and the Phanerozoic accreted terranes, along with the structural and chemical modifications of the lithosphere associated with the Sevier and Laramide orogenies; batholiths associated with Phanerozoic magmatic arcs and the related orogenic belts; how did this magmatism impact the ancient lithosphere of North America more so in the Northern Rockies than perhaps anywhere along the Cordilleran margin. This basement involvement in Cordilleran deformation may have been controlled by the unique ancestral structure of the lithosphere (e.g., structures like the Lewis and Clark line) or the dynamics of terrane collision and accretion along the Idaho suture zone, Cheyenne belt, Black Hills/THO, etc.
e. Structure AND composition of the lithospheric mantle—what is its composition, when and how did it form, nature of the 7x layer, physical and chemical properties it implies.
f. Interaction of the ancient lithosphere of the Wyoming craton with the Yellowstone hot spot and associated Snake River Plain volcanism and the shallow subduction regime of the Farallon plate.
g. Fate and impacts of slabs, drips, plumes, windows, delamination, ....Consequences for structures, magmatism.
h. Additional Questions Suggested by Gene Humphreys:
a. What is the timing and are the processes for early craton mobility and then stabilization (changes in forces or strength, and due to what)?
b. How prominent is post-Archean craton destruction, and what are the processes involved in its destruction? How do we know?
c. What is the global importance of cratons: e.g., on protecting and stabilizing continents, and on influencing patterns of tectonics & mantle flow?
d. By what means did the Al-Fe rich compliment to depletion get removed from cratons?
e. What controls the depth extent of cratons?
f. The creation of shields seems to roughly involve Archean craton creation and Proterozoic shield assembly. What tectonic insight is gained by understanding this transition?
g. Is the evolution from Hadean stagnant lid to Phanerozoic plate tectonics progressive, or does it involve fundamental transitions in state?
h. By what processes does mantle metasomatism occur, and what are its effects on composition, strength and density?
i. How much variety is there in the processes of craton creation? Is South Africa fundamentally different than North America? E.G., the role of mantle plumes verses tectonic-like processes?
1:45-4:00 Small Working/Writing Groups (Break as needed). [Small group discussions in breakout groups; report out to whole group. Outcome: detailed outline of a) Big questions, b) Evidence from EarthScope science (maps, figures, graphs, datasets, data-products such as tomograms....), c) Key findings and interpretations, d) References. Group work will be recorded in Google Docs for future development].
4:00-5:00 Report Out of Writing Groups. General Discussion and input from whole group.
Dinner Downtown (TBD)
January 13 (Sunday) Montana State University Student Union Building Room 230
8:00 Breakfast service SUB 233; Networking
Outcomes Day
8:30-9:30 Whole group Discussion I—Education and Outreach Opportunities, Led by
Elisabeth Nadin, ESNO
Whole group brainstorming about how to translate EarthScope science to broader audiences: a) K-12 teachers (curriculum, partnering with established groups like IRIS, UNAVCO, NESTA....); b) Undergraduate studies (SERC, ....) including minority institutions (e.g. tribal colleges); c) Graduate studies (COMPRES, CIG...), d) Informal education for general public.
9:30-10:00 Break Out Groups II
Finalize outlines; confirm writing assignments; timelines
10:00-11:00 Whole Group Discussion II—Writing Plan
a. Report out of status of each writing group
b. Workshop report (Conveners; input about key points of report).
c. Themed Journal Volume (Geosphere, other????); Identify outlet.
a. Article title/topic; writing team
b. Data available
c. Recruitment of other authors?
d. Follow on theme sessions at GSA, AGU (who takes responsibility for organizing)?
e. Timeline
f. What's Missing? Conspicuously absent is any input using geodetics, lidar, neotectonics, etc.
11:00 Wrap up: Reflections on progress made; next steps needed
Distribute box lunches for travel.
Depart for airport as needed to catch flights.
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