Carleton University’s groundbreaking research at Crawford Lake in Milton, Ontario, under the stewardship of environmental geologist Tim Patterson, has identified the lake as the defining site for the commencement of the Anthropocene epoch. This epoch marks a new geological era influenced significantly by human activity’s global impacts.
Patterson’s team employed innovative techniques, extracting “freeze cores” from Crawford Lake’s bed, unveiling a pristine record of industrial emissions, radioactive elements, and other chemical signals deposited in annual sediment layers. These freeze cores, towering up to two meters tall, were meticulously analyzed by Patterson and a collaborative team, including Indigenous partners, revealing crucial evidence supporting the start of the Anthropocene circa 1950.
“This recognition showcases the sensitivity of our world to human activity,” expressed Patterson, emphasizing the significance of Crawford Lake’s ability to archive indicators marking the Anthropocene’s beginning: plutonium isotopes from nuclear testing, fly ash linked to fossil fuel combustion, and ecological shifts.
The declaration of Crawford Lake as the “golden spike” for the Anthropocene, announced by the Anthropocene Working Group (AWG), solidifies its place as the reference point for a new epoch that underscores the profound human-induced transformation of Earth’s climate and biosphere.
Patterson’s freeze core expertise, honed over 25 years, offered a compelling lens into Crawford Lake’s historical stratigraphy. The cores, capturing thin annual layers, illuminate the fallout of airborne substances, including fly ash from World War II and industrial emissions from nearby Hamilton’s steel plants.
The interdisciplinary collaboration, co-led by Patterson and Brock University’s Francine McCarthy and Martin Head, integrates cutting-edge methods to scrutinize and interpret the lake’s sedimentary record, including microscopic analysis of shelled microorganisms sensitive to human-induced changes.
Crawford Lake’s selection as the Anthropocene’s starting point crowns years of meticulous research, positioning Canada at the forefront of geological exploration. The freeze cores from Crawford Lake, set to be archived at the Canadian Museum of Nature, will be a repository of Earth’s narrative, serving as an invaluable resource for understanding our past and future.
