Cretaceous (Albian-Aptian) conifer wood from Northern Hemisphere high latitudes: Forest composition and palaeoclimate

Permineralised conifer wood is abundant in Cretaceous (Albian–Aptian) sediments in high northern latitudes (N60°). The wood provides evidence of conifer-dominated forests that extended across the northern polar regions during greenhouse periods when the climate was warmer than today. This study investigates the composition of the Cretaceous (Albian–Aptian) high latitude Northern Hemisphere conifer forests using wood from Spitsbergen, and Ellesmere and Axel Heiberg islands in the Canadian Arctic Archipelago. Identification of the fossil woods indicates that the conifers included Pityoxylon, Piceoxylon, Laricioxylon, Protopiceoxylon, Palaoepiceoxylon, Taxodioxylon, Juniperoxylon, Protocedroxylon, Araucariopitys, Xenoxylon, Cupressinoxylon and Taxaceoxylon. This study shows that Spitsbergen was dominated by Taxodioxylon (25%) and in the Canadian Arctic Pityoxylon (33%) was dominant. Climate analysis of the conifers indicates that the northern Cretaceous (Albian–Aptian) forests of Svalbard grew in moist cool upland areas with warmer temperate areas in the lowlands, probably with rivers and/or swampy areas present. The forests of the Canadian Arctic probably grew under slightly cooler conditions than on Svalbard, similar to northern Canada today.