| colspan = 2 | ''Veins;'' The solid, essentially infusible form of petroleum is called [[pyrobitumen]]. It occurs in veins [[length::1 mm]] to [[length::8 m]] across and appears to have been injected or is a dead seepage. | | colspan = 2 | ''Veins;'' The solid, essentially infusible form of petroleum is called [[pyrobitumen]]. It occurs in veins [[length::1 mm]] to [[length::8 m]] across and appears to have been injected or is a dead seepage. |