Mark is a highly regarded ore deposits researcher, professor, and advisor to mining companies worldwide. His research focuses largely on the geochemical processes at work in the rock-fluid-gas interactions that create mineral deposits. Mark's knowledge of all kinds of ore deposits is comprehensive, with a particular focus on epithermal gold-silver, porphyry copper-molybdenum, and volcanogenic massive sulfide base-metal deposits. This knowledge is based on a unique combination of careful field observation and theoretical modeling: Mark has developed computer models that numerically simulate ore-forming processes and give insight into how veins and alteration form and how metals are deposited. These insights are directly applicable to minerals exploration, and major mining companies have sought Mark's understanding of ore-forming processes. He also investigates the geochemistry of geothermal systems. Mark has been a professor at the University of Oregon since 1979. He has a BA in geology from Carleton College and MS and PhD degrees from the University of California at Berkeley. He is recipient of two of the Society of Economic Geologists' highest awards, the Brian J. Skinner Award (for outstanding papers published in Economic Geology, the top ore deposits research journal) and the Lindgren Award (for young scientists making outstanding contributions to economic geology).