THOMPSON FIELD FORUM REPORT: Age and Carving of Grand Canyon: Toward a Resolution of 150 Years of Debate

The age and evolution of the Grand Canyon, in the western USA, have been debated since J.W. Powell’s exploration of the Colorado River in 1869. This paper reports results of a 2019 GSA Thompson Field Forum that honored the 150th anniversary of Powell’s first trip. INTRODUCTION The 2019 GSA Thompson Field Forum, “Age and Carving of Grand Canyon: Toward a Resolution of 150 Years of Debate” involved 28 researchers and young scientists (Table 1) who discussed the evidence for the age, geomorphic evolution, and incision history of Grand Canyon in the context of recent advances and ongoing debates. The objective was to emphasize the power of