What do you do?
I study structure and tectonics of mountain belts, mostly in western U.S., the Andes, and the Alpine-Himalayan system. I also worry about tectonics and evolution, tectonics and climatic change, fragments of oceanic crust and mantle formed at spreading centers now found in continents (ophiolites).

Why should the general public be interested in what you do?
It's important for understanding how the Earth works, how it has changed over time, and what the earthquake hazard is of the western Great Valley.

Why does it interest you?
I am interested in how the Earth works, and the history of how it has worked through time. Or to quote Will Durant, "Civilization exists by geologic consent - subject to change without notice". We all need better to understand the Earth and how it works in order to ensure a sustainable future for our children and children's children.

What major advances/discoveries have occurred in your research field over the last 10 years?
I discovered evidence linking Antarctica to North America some 750 million years ago (SWEAT hypothesis). We are now able to correlate results from the Ocean Drilling Project (ODP) on the structure of the oceanic crust at mid-oceanic ridges with that we see on land in ophiolites. This result should help us better to use ophiolites to interpret the processes of sea-floor spreading and plate tectonics in times prior to that represented by any oceanic crust preserved in the present oceans (before 186 million years ago).