Asimow, Jahren, and Randerson receive 2005 James B. Macelwane Medal

It is my great pleasure to present my friend and colleague, Paul Asimow, recipient of one of this year's three James B. Macelwane Medals. Paul is a petrologist interested in the origins and evolution of basaltic magmas, and he is being recognized for a series of profoundly insightful papers on the energetics of decompression melting and how it controls the compositions of the oceanic crust and upper mantle. The significance of what Paul has done comes from the simplicity of the question that first inspired him: How should we describe the way the mantle melts as it upwells during convection? The importance of the problem is obvious; this is how the Earth makes most of its crust, and so it is the starting point for most of geology But does it sound like something we already understand? Wasn't I taught this as an undergraduate? Paul's first and perhaps most important contribution was to recognize, as a second‐year graduate student working with Ed Stolper [California Institute of Technology (Caltech),Pasadena],that the explanation of mantle melting we were telling each other was a Rube Goldberg device masquerading as physical theory.