My primary research interest is in the genesis and evolution of the Earth's crust, in the ocean basins, in arcs, and in continents. To these topics I bring the perspective that reactions between melt and rock during transport through the upper mantle are as important as melting, mixing, and crystal fractionation processes in producing different crustal bulk compositions in different tectonic settings. In considering the genesis of continental crust, I've adopted the simple assumption that the continents have an igneous composition, and can be interpreted in terms of igneous processes occuring today. The Archean Earth may have been hotter, on average, but we can look at especially hot places today to infer the nature of Archean petrogenesis. Over the years, I have become more and more fascinated with pattern formation during fluid transport processes. And finally, I've been very fortunate to work with a large number of tolerant geophysicists (Jack Whitehead, Einat Aharonov, Steve Holbrook, Marc Spiegelman, Greg Hirth, Jun Korenaga, Matthew Jull, and others) who have led me into the world of geodynamics. I am really grateful to them, particularly Greg Hirth with whom I share a lab and many of the following research projects.