Volcanos – the gift that keeps on giving

The Smoking Hills Formation of Arctic Canada represents a Cretaceous metalliferous black shale named after auto-combusting exposures in Ingniryuat, Northwest Territories. This area was also named The Smoking Hills by the Franklin Expedition after the ever-present clouds of sulphuric acid smoke produced. Similar burning Cretaceous mudstones occur in Yukon, and northern Alberta, as well as western Greenland (as recorded in the Viking Sagas). These burning shales reflect deposition during OAE 2 and 3 events across the Arctic region. Metal in the Smoking Hills Formation are enriched over 1000x average shale values. The metal concentrations strongly correlate with heulandite content, an alteration product of volcanic glass, suggesting an origin related to volcanic loading. Abundant bentonite beds in the Smoking Hills Formation support deposition during active volcanism. This is further consistent with the eruption history of the High Arctic Large Igneous Province to the north, or Cretaceous arc related volcanics to the west. These metals are now being recycled into the otherwise modern pristine Arctic environment, generating hyper acidic waters (recording negative pH values) with extremely high metal concentrations orders of magnitude higher than safe drinking levels. Cretaceous eruptions are still driving widespread deleterious environmental impact today.