Unscrambling the Midcontinent Rift and Grenville Front and their implications for the assembly of Rodinia

Conveners: Seth Stein, Carol Stein, Randy Keller and Chris Scotese

Location: Northwestern University

Date of Workshop: July 26-28, 2018

Workshop Report

The workshop's goal is to explore the complex and poorly understood relations in the central U.S. between major structures such as the Midcontinent Rift and Grenville Front and their implications for the assembly of Rodinia. New ideas are evolving, driven in part by EarthScope studies of the Midcontinent Rift, southern Appalachians, and Illinois Basin and surroundings. These provide an opportunity to revisit major issues about the region's Precambrian tectonic evolution. We will synthesize EarthScope and other geological and geophysical data to explore issues including:

1) Is there a Grenville Front in the central U.S?

2) What crustal blocks were involved and what were their boundaries?

3) What are the new implications for the assembly of this part of Rodinia?

4) What is the tectonic significance of differences between the east and west arms of the MCR?

5) What additional geologic and geophysical evidence and modeling can clarify the issues related to the Grenville Front in the central U.S. and the southward continuation of the MCR's east arm?

6) How and why does the MCR differ from other rifts in North America and other continental interiors? Why did their Phanerozoic behavior?

7) What insights can the MCR provide about the processes of continental rifting and passive margin evolution?

We will invite participation from interested researchers with regional and/or disciplinary interests. We plan to synthesize existing data from various disciplines, assess what is currently known and unknown, formulate plausible hypotheses, and suggest strategies for further research.