Evaluating the controls on early dolomite formation in ancient rocks is challenging due to a lack of reliable proxies that can be used to infer microscale environmental conditions of dolomitization. Corlett and Jones examine sedimentological and geochemical differences between dolomite- and calcite-filled burrows in Devonian rocks from the Lonely Bay Formation, in the Northwest Territories, Canada. An integration of various geochemical and sedimentological analyses explains why dolomite formed in some of these burrows whereas others are filled with calcite. The results of this study highlight the role of sulphate-reducing bacteria, oxygenation, and different types of organic material in early dolomite precipitation.
Petrographic and geochemical contrasts between calcite- and dolomite-filled burrows in the Middle Devonian Lonely Bay Formation, Northwest Territories, Canada: implications for dolomite formation in Paleozoic burrows by Hilary J. Corlett and Brian Jones