A primary marker at Crawford Lake, Canada, starts the Anthropocene epoc

pyroclast writes: The Anthropocene Working Group have put forward Crawford Lake, in Canada, as a Global Boundary Stratotype Section and Point (GSSP) for the Anthropocene. A GSSP is an internationally agreed-upon reference point to show the start of a new geological period or epoch in layers of rock that have built up through the ages.

The team has gathered core sample sections from a variety of environments around the world, from coral reefs to ice sheets. Samples from a range of these sites were then sent for analysis to the University of Southampton's GAU-Radioanalytical labs at the National Oceanography Centre in Southampton. Researchers there processed the samples to detect a key marker of human influence on the environment — the presence of plutonium.

Professor Andrew Cundy, Chair in Environmental Radiochemistry at the University of Southampton and member of the Anthropocene Working Group, explains: "The presence of plutonium gives us a stark indicator of when humanity became such a dominant force that it could leave a unique global 'fingerprint' on our planet.

Other geological indicators of human activity include high levels of ash from coal-fired power stations, high concentrations of heavy metals, such as lead, and the presence of plastic fibres and fragments. These coincide with 'The Great Acceleration' — a dramatic surge across a range of human activity, from transportation to energy use, starting in the mid-20th century and continuing today.