Open AccessStoregga tsunami deposits in a coastal lake on Suouroy, the Faroe Islands
Author(s) -
GRAUERT MARIANNE,
BJÖRCK SVANTE,
BONDEVIK STEIN
Publication year - 2001
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/j.1502-3885.2001.tb01045.x
Subject(s) - geology , erosion , foraminifera , clastic rock , structural basin , geomorphology , paleontology , oceanography , geochemistry , benthic zone
Presumed deposits of the Storegga tsunami have been recognized in a coastal lake situated 4 m a.s.l. on the island of Suouroy, the Faroe Islands. The stratigraphy in the lake reveals a major erosion and redepositional event. The deposited material ranges from sand and sandy gyttja, with marine shell fragments and foraminifera, to gyttja with rip‐up clasts, wood fragments and thin sand layers. Diatom analysis indicates that the deposit contains 5–8% polyhalobous (full marine) species, decreasing to 1–2% in the undisturbed lacustrine gyttja above. The tsunami event was dated to some time between 7300 and 6400 14 C yr BP. Lithostratigraphic profiles in the lake suggest that at least two large waves inundated the basin. The first and largest wave eroded most or all of the sediments previously deposited in the basin. The next wave caused minor erosion of the re‐deposited material. The waves deposited two generations of sand overlain by organic conglomerates, after which followed a unit of suspension material and normal lacustrine gyttja.