Our guest on ST is Dr. Stephen Marshak, Professor of Geology and Director of the School of Earth, Society, and Environment at the University of Illinois, Urbana-Champaign. As a part of Earth Week, the University of Tulsa's Geosciences Department invited Dr. Marshak for two speaking engagements that occurred here on the TU campus yesterday (the 17th) at noon and 7:30pm. The latter was an address entitled "What's Happening Deep Beneath the Midcontinent?: Tectonics, Earthquakes, and the EarthScope Project in North America's Interior." Dr.