Point of View - Richard looks up a hill. He points out a layer of grey sediment that contains rocks of all sizes. The grey sediment sits on top of a different layer of brown sedimentary rock.

Richard: You see all that unconsolidated lots of boulder, lots of mud, sand, etc. from there up is all up until the soil horizon which is right below the tree roots just well, actually even the tree roots are it, this is all glacial till from the last ice age, Wisconsin ice age, about 10 to 14,000 years ago.

A graphic showing the top half of North America covered by a glacier is shown. Richard points to the brown layer of rock below the glacial till.

Richard: But this level here is the 70, about 74 million year old Wapiti Formation. And these rocks are part of it as well. So that's the situation. 74 million year old rocks overlain by a 14,000 year old glacial, unstratified glacial till.

Lisa: In geology speak we call that an unconformity.