Crustal structure and origin of the Eggvin Bank west of Jan Mayen, NE Atlantic. Issue 1 (21st January 2017)

• Record Type: Journal Article
• Authors: Tan, Pingchuan; Breivik, Asbjørn Johan; Trønnes, Reidar G.; Mjelde, Rolf; Azuma, Ryosuke; Eide, Sigurd
• Is Part Of: Journal of geophysical research. Volume 122:Issue 1(2017)
• Page Start: 43
• Page End: 62
• Publication Date: 2017-01-21
• Subjects: Eggvin Bank -- Vp and Vs model -- seismic refraction -- Iceland Plume; Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1002/2016JB013495
• Languages: English
• ISSNs: 2169-9313

Abstract

Abstract: The Eggvin Bank, located between the Jan Mayen Island and Greenland, is an unusually shallow area containing several submarine volcanic peaks, confined by two transforms on the Northern Kolbeinsey Ridge (NKR). We represent P and S wave velocity models for the Eggvin Bank based on an Ocean Bottom Seismometer profile collected in 2011, showing igneous crustal thickness variations from 8 km to 13 km. A 2–5 km increase is associated with two separate 20–30 km wide segments under the main seamounts. The oceanic crust has three layers: upper crust (L2A: 2.8–4.8 km/s), middle crust (L2B: 5.5–6.5 km/s), and lower crust (L3: 6.7–7.35 km/s). Both the thick layer 2(A/B) and the high ratio of layer 2(A/B) thickness to total crustal thickness indicate that secondary, intraplate magmatism built the seamounts of the Eggvin Bank. The seamount in the north where the crust is thickest has a flat top indicating subaerial exposure but is deeper than those with rounded tops in the south and is therefore probably older. Comparing lower crustal seismic velocity with crustal thickness also indicates that the degree of mantle melting may be higher in the north than in the south. An enriched mantle source presently feeds the NKR magmatism and probably influenced the Eggvin Bank development also at earlier times. To what extent the Eggvin Bank has been influenced by the Iceland plume is uncertain, both an enriched mantle component and elevated mantle temperature may have played a role at different times and locations. Key Points: A seismic refraction and reflection study of the Eggvin Bank at the northern Kolbeinsey Ridge V p and V s models of the Eggvin Bank show 8–13 km igneous crustal thickness The Eggvin Bank is created by melting of an enriched mantle source both on and off axis