The Lonely Bay Formation, located to the west of Great Slave Lake, Northwest Territories, Canada, is a thick-bedded limestone succession that includes four facies that are characteristic of a Devonian middle-ramp depositional setting. One facies in the Lonely Bay Formation is intensely bioturbated with some burrows filled with calcite and others with dolomite. The calcite-filled burrows are found close to the paleo-shoreline of the Canadian Shield, whereas the dolomite-filled burrows are found in deeper ramp deposits. In the calcite-filled burrows the parent burrows, each surrounded by a diagenetic halo, are readily apparent, whereas the dolomite-filled burrows are largely devoid of original structures. Each burrow type has its own distinctive geochemical suites of rare-earth-elements (REE), trace-elements, and δ18O