Allenby Formation

The Allenby Formation is an Early Eocene sedimentary formation in southern British Columbia, deposited in the Princeton and Tulameen basins as rivers, lakes, wetlands, and volcanism reshaped the landscape. Its most unusual feature is a repeated alternation of coal and chert, with about 49 known cycles formed rapidly under silica-rich volcanic influence, a pattern unknown from any other fossil locality. The formation is a major Canadian fossil lagerstätte, preserving a warm-temperate upland ecosystem with abundant insect, fish, plant, pollen, and fungal remains. Especially notable are the anatomically preserved fossils of the Princeton Chert and a giant Titanomyrma queen reported in 2023.

British Columbia · Canada