This morning I finished my banquet of science with a session focused on subduction, including rocks that I know fairly well in California. Specifically, how does subduction start and stop? The thrill today was the idea that the keys to the problem lie in ophiolites, those odd packages of deep oceanic rocks found stranded on the continents. The speakers argued that while many ophiolites reflect the processes of ordinary, ongoing subduction (like colliding continents and islands and so on), some came about from the initiation of subduction, for which there are several models. Now these models can be tested, not just by expensive oceanic drilling and mapping expeditions, but also by plucky field geologists on ophiolites around the world.
I enjoyed three things about the session. One, it featured computer models that show realistic-looking geology, things that made the audience very attentive. Two, it featured some tempting field sites to visit in my own neighborhood. And three, most of the speakers were major scientists in the big conversation, people I always seek out when they appear at a meeting. And, of course, what I learned will surely inform what I write.