The Vesterisbanken Seamount (Greenland Basin): Patterns of morphology and sediment distribution

• Published in: Marine Geology
• Main Authors: Hempel, Peter, Schreiber, R., Johnson, L., Thiede, Jörn
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 1991
• Subjects: Greenland; Greenland Basin; Greenland Sea
• Online Access: https://oceanrep.geomar.de/id/eprint/33207/; https://oceanrep.geomar.de/id/eprint/33207/7/Hempel.pdf; https://doi.org/10.1016/0025-3227(91)90215-P

A closely spaced grid of seismic reflection profiles has permitted a description of the structure of the Vesterisbanken Seamount (Greenland Sea) and the distribution of the surrounding sediments. This isolated seamount is situated at 73°30′N, 9°10′W in the Greenland Basin and rises from the basin floor at a water depth of about 3100 m to ∼ 130 m below sea level; the maximum inclination of its slope is 26°. It is of basaltic origin, and reveals chaotic reflectors on the seismic profiles. No inhomogeneities are visible within the volcanic rocks of Vesterisbanken and the basement complex surrounding it. Dredge samples from the summit of Vesterisbanken reveal an age of ∼ 100,000 years. In the seismic records, there was no sediment cover discernable on top of or on the flanks of the seamount. At the base of Vesterisbanken, the seismic reflection characteristics suggest an alternation of sediments and basaltic rocks, the latter probably being the result of young lava flows. In some places the volcanic rocks disturb the sedimentary sequence to such a high degree, that the stratification is virtually eliminated. Volcanic activity also occurs in the vicinity of the seamount: for example, about 20 km northwest of Vesterisbanken an intrusion has pierced through 1000 m of sediment, almost reaching the seafloor. The sediment thickness is variable and it smooths the irregular basement topography. In addition, the sediment is characterized by local unconformities associated with onlap structures.