Late Quaternary terrigenous plant and coaly fragments found at Vestnesa Ridge, Fram Strait: implications for postglacial plant colonization at Svalbard

Abstract

One of four marine cores of glacial sediments collected from a water depth of about 1200 m at Vestnesa Ridge (west of Svalbard) contained small fragments of coal, charcoal and moss. This material was restricted to a single level, and 14C dating of bivalves both above and below indicates an age of c. 18.0–15.5 kyr BP. Chemical analyses of the coal indicate that the provenance area was from the northern part of Andøya, North Norway. The moss fragment was identified as Aulacomnium turgidum, which is a well-known species from the northern part of Andøya, which was an ice-free refugium with tundra vegetation during the Weichselian maximum. One small piece of charcoal with reasonably well-preserved cell structures is derived from burnt Salix sp. These findings are important, because they demonstrate the presence of drift ice carrying organic material from the northern part of Andøya towards the west coast of Svalbard during Heinrich event H1, an event of extensive ice-rafting in the Nordic seas. This also implies that some components of the vascular plant communities growing on Svalbard today, might originally have been imported as seeds floating on sea ice, before stranding along the coast of Svalbard. The plant colonization of Svalbard can thus have started already during Heinrich event H1. The finding of charcoal can only be explained by a fire due to lightning and not by campfire, because the first human population arrived in northern Norway at a much later time (probably during Preboreal). The charcoal is thus from the oldest known wild fire in Norway.