Athro, Limited Earth Science K-T Field Trip

Certain ants in this region build mounds some 30 cm high. To prevent the wind from blowing away the mounds, the ants cover them with a layer of small rock fragments. The ants select rock fragments some 3mm in diameter from the area around the nest, and bring them back to cover the mound. Most of these are weathered fragments of ironoxide concretions. Coincidentaly, this also happens to be about the size of most late Cretaceous and Paleocene mammal teeth. If the ants happen to live near a deposit that contains a concentration of these teeth, they will also colect these fossil teeth and place them on the surface of their mound. Thus examining the surfaces of these anthills is an effective technique for searching for mammal tooth localities.

You may click on the stratigaphic colum on the right side of the screen to explore a specific part of the section, or return to a photo of the Iridium Hill area.