Summary: My talk consists of two parts. The first describes recent advances in understanding of plate tectonics as we see it today, including the formation of oceanic core complexes at slow-spreading mid-ocean ridges, the concept of subduction factory at convergent margins, and the role of partial melting in continental collision. The second part of the talk will address the onset of plate tectonics on Earth. There is vigorous debate today about when plate tectonics began. For some, plate tectonics has been active all along since the Hadean (earliest planetary dynamics), but for others, plate tectonics started 3 billion years ago or even only 1 billion years ago. I will attempt to clarify the elements of this debate using new data from Hadean time, geological observations of classic Archean terranes, and the value of plate-tectonic markers, such as preserved high-pressure rocks that are found only in modern subduction systems (younger than 1 billion years).

Presenter biography: 

Education:
Ph.D., 1986, Monash University, Australia      
Diplôme d’Etudes Approfondies, 1981, Université de Montpellier II, France 
Maîtrise es Sciences, 1980, Université de Montpellier II, France 
 
Positions:
University of Minnesota  
1997 – present:  Professor 
•    2018 – 2023: George and Orpha Gibson Chair of Geoscience  
•    2003 – present: Academy of Distinguished Teachers (UMN) 
1991 – 1997: Associate Professor  
1985 – 1991: Assistant Professor  
 
Sabbatical and other leaves: 
2006- 08: University of Lausanne, Switzerland – Professor  
03/98: University of Graz, Austria (invited)  
04/97-06/97: ETH – Zürich, Switzerland (invited) 
09/96-03/97: University Montpellier II, France (invited) 
09/91-08/92: University Montpellier II, France (McKnight Land-Grant Professor)