Life and Death of a Craton: A 4D EarthScope perspective on the role of the Wyoming Craton in the evolution of North America

Conveners: David Mogk, Paul Mueller, Carol Frost, Ray Russo

Location: Montana State University

Date of Workshop: January 11-13, 2019

Workshop Report

This workshop will focus on the architecture and evolution of regions beneath and adjacent to the Wyoming Craton, and the significant advances in research in this area that have resulted from the EarthScope program.  The Wyoming Craton includes the oldest crustal components preserved in North America. It is the site of vertical growth of the continent through episodic magmatic events extending back to ~4.0 Ga and continuing through contemporary magmatism in the Yellowstone-Snake River Plain system, and lateral growth of the continent through tectonic and magmatic accretion of crustal components that have added to, or modified, the North American continent from the Archean through to the present. This workshop will integrate extant geological, geochemical, geochronological, and geophysical data into coherent and comprehensive models of the composition and architecture of the crust-mantle system beneath and adjacent to the Wyoming craton throughout Earth history.  We will also examine remaining uncertainties and develop a set of research goals for future work.   Topics that will be addressed at this workshop include:

1. Obtaining a better understanding of the lithospheric structure and evolution within and adjacent to the Wyoming craton. This includes a) imaging of velocity, structure and thickness of the crust and sub-cratonic mantle, and b) establishing the geochronologic framework of crustal evolution, use of isotopic tracers to distinguish source areas and to demonstrate pathways in global geochemical cycling, and determination of the rates of geologic/geochemical processes (from mantle to surface and back).

2.  Development of a more complete understanding of the interaction of Wyoming craton lithosphere with the Yellowstone hot spot and associated Snake River Plain volcanism and with the shallow subduction regime of the Farallon plate.

3. Broader understanding of the deformation of North American continental lithosphere, including ancient and active deformation: the current state of stress in the lithosphere, accommodation of the Belt basin, reactivation of earlier structures that influence Laramide, Sevier, and Basin and Range structures, neotectonics in the Rocky Mountain seismic belt, and structural control of metallogenesis.  

4. Better understanding of 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.

5. Develop education and outreach opportunities to serve educators at all levels.