Enviar por SMS: Gray clay (Malpass clay) in the west Eugene Wetlands and the Willamette Valley is weathered and redeposited ash from Mount Mazama / authors: Karin E. Baitis, Bureau of Land Management (retired), Eugene District Office, Springfield, Oregon ; Gregory J. Retallack, University of Oregon, Department of Geological Sciences, Eugene, Oregon ; Michael E. James, James Geoenvironmental Services, Eugene Oregon.