Transition zone between the Lorrain Quartzite and Gordon Lake siltstone, Lonely Lake Member of the Lorrain Formation; Proterozoic, Huronian Supergroup: 2.2-2.5 billion years old; Echo Bay Road, Sault Ste Marie
Feldspathic siltstone. The rock is a sedimentary rock composed of fine grains of feldspar and quartz. The feldspar grains give the rock its pale pink colour.