Black Soot

Soot (pron.: /ˈsʊt/) is impure carbon particles resulting from the incomplete combustion of hydrocarbons. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as coal, cenospheres, charred wood, petroleum coke, and so on, that may become airborne during pyrolysis and that are more properly identified as cokes or chars

Note: the rafters of the Halls of Hasvik had a thick layer of sod, from many centuries of burning Oil fires below. Eric was cleaning those rafters during his time at Hasvik