Established in 2009 by the Subcommission on Quaternary Stratigraphy, the Anthropocene Working Group is a gathering of scientists who have worked to determine whether the mid-20th century marks the beginning of a new phase of geologic history. It is chaired by Colin Waters, a geologist at the University of Leicester, and its members have included academics in Australia, Canada, China, Japan, Poland, Switzerland, Britain and the United States. They hail from diverse disciplines including archaeology, chemistry and geology.