Vesteris Seamount: An enigma in the Greenland Basin

Cherkis, Norman Z.; Steinmetz, Stefan; Schreiber, R.; Thiede, Jörn; Theiner, Jürgen

doi:10.1007/bf01224746

Cited by 10 publications

(11 citation statements)

References 8 publications

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“…This may have to do with the increasing distance from the main source area which, based on the geochemical characteristics of these ashes, is inferred to be mainly Iceland (Bitschene et al, 1989;Werner et al, this volume). For a few ashes it has been assumed that volcanism on Jan Mayen may be the origin (Werner et al, this volume), but the young intraplate volcano Vesterisbanken (Cherkis et al, 1994) probably also has to be considered. Whether this applies to the volcanic ashes at Site 913 and 908 must remain open, and potential other sources have to be considered.…”

Section: Implications For the Tectonic And Volcanic History Of The Nomentioning

confidence: 99%

The Paleoceanographic History of the North Atlantic-Arctic Gateways: Synthesis of the Leg 151 Drilling Results

Thiede¹,

Myhre²

1996

Proceedings of the Ocean Drilling Program

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During Leg 151, seven locations were drilled in the western Norwegian-Greenland Sea, in Fram Strait, and on the Yermak Plateau. These sites allow us to address the paleoceanographic and climatic history of the surface-and bottom-water masses in high Northern Hemisphere deep-sea basins, of the mode and pattern of water exchange between the Arctic Ocean and the Norwegian-Greenland Sea through Fram Strait, and the Neogene and Quaternary history of glaciation of the surrounding shelves and land regions. A detailed and well-developed pelagic biochronology has been defined for all of the sites, allowing correlation of their stratigraphic record to sedimentary sequences from lower latitudes. Except for a few short-lived interruptions caused by hiatuses, the entire paleoceanographic history from the Eocene, when the Norwegian-Greenland Sea was small and narrow, to the Quaternary can be described.When the Norwegian-Greenland Sea was small and consisted of a sequence of narrow basins, surface water penetrated the area from the North Atlantic Ocean and brought temperate to subtropical siliceous faunas and floras. Only during the latter part of the Oligocene and the early part of the Miocene did cool to temperate water develop. The first signs of marine ice covers or the presence of icebergs developed during the late Miocene, earlier on the Iceland Plateau, later in the northern and eastern part of the investigated region. The influence of the marine ice covers and of the influx of icebergs, first from Greenland and later from northwestern Europe, increased during the course of the Pliocene until it reached an important threshold approximately 3 to 4 Ma off southern Greenland and only 2.6 Ma in Fram Strait and off northwestern Europe. This is interpreted as an increase in the dynamics and growth of the ice caps on either side of the Norwegian-Greenland Sea.In the course of the Pliocene and Quaternary, rapid changes between glacials and interglacials can be observed. Some of the sediment properties reflect Milankovitch frequencies: in the earlier part of the history these were mainly obliquity-related; during the past 600-700 k.y. that were mainly eccentricity-related. A temperate interval in the middle Pliocene interrupted the history of the delivery of ice-rafting even in Fram Strait and coincided well with the development of boreal forests on northeastern Greenland. Site 907 on the central Iceland Plateau received large quantities of volcanic ash related to the volcanism developed on Iceland and potentially also on Jan Mayen. Site 908 on the Hovgàrd Ridge allows us to address the tectonic history of the opening of Fram Strait and of the subsidence of the Hovgárd "microcontinent." The drill sites of the Yermak Plateau are heavily influenced by sediments related to the development of glaciation on Svalbard. Site 910 penetrated a clearly overconsolidated part of the sequence and seems to have been overridden by the Svalbard ice cap, prior to -600 ka.

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Section: Implications For the Tectonic And Volcanic History Of The Nomentioning

confidence: 99%

The Paleoceanographic History of the North Atlantic-Arctic Gateways: Synthesis of the Leg 151 Drilling Results

Thiede¹,

Myhre²

1996

Proceedings of the Ocean Drilling Program

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“…We do not yet have seismic data to investigate if sedimentary strata have been uplifted and eroded in the area. However, we know that the Vesterisbanken seamount probably formed by subaerial magmatism at <1 Ma [ Cherkis et al , 1994; Haase and Devey , 1994] so we cannot rule out secondary mantle processes as a shaping factor of the Greenland Basin.…”

Section: Sediment Thickness Mapmentioning

confidence: 99%

Prediction of sediment thickness in the Norwegian–Greenland Sea from gravity inversion

et al. 2006

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[1] We explore the feasibility of inverting freely available altimetry-derived gravity grids for sediment thickness on oceanic crust. A four-layer Earth model is adopted, assuming that the gravity signal from the base of the sedimentary layer can be fully isolated from the observed free-air gravity. The following additional data are required: (1) shipboard bathymetry for reliable Bouguer correction, (2) oceanic crustal ages to correct for gravity anomalies related to the thermal history of lithospheric breakup and seafloor spreading, and (3) some wide-angle seismic observations of sediment thickness. A fixed relationship between the base of the sedimentary layer and the Moho is also required because of limited gravity resolution at large depths. The final inversion setup searches for three control parameter values (density of uppermost sediments, density of oceanic crystalline crust, and thermal diffusivity of mantle rock) that minimize misfit between the Earth model and observations. Applied to the Norwegian-Greenland Sea, the inversion successfully predicts locations of >20-25 km wide depocenters and crystalline crustal highs, yet $1 km thickness errors are common even in well-constrained areas. The largest errors are associated with underplated crust, active mid-ocean ridges, and the continent-ocean boundary, indicating locally incorrect assumptions of mantle thermal structure and crystalline crustal thickness. The thicknesses of >4 km thick submarine fans are underpredicted, probably because of too low sedimentary densities in the Earth model. If these limitations are acceptable or do not apply because of simple crustal structure, gravity inversion may be used for mapping regional sedimentary patterns, e.g., in the Arctic Ocean.

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“…There is, however, poorly understood magmatism at distance from the Iceland plume, occurring from the Miocene on east Greenland [ Storey et al , 2004], to recent on Jan Mayen [ Trønnes et al , 1999] and the Vesteris Seamount [ Cherkis et al , 1994] (Figure 1). Mantle plume theory has lately been under attack based on observations that seemingly do not fit or that can have other explanations [e.g., Anderson , 2000; Natland and Winterer , 2005; Foulger and Anderson , 2005].…”

Section: Introductionmentioning

confidence: 99%

Neogene magmatism northeast of the Aegir and Kolbeinsey ridges, NE Atlantic: Spreading ridge–mantle plume interaction?

Breivik

Faleide

Mjelde

2008

Geochem Geophys Geosyst

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[1] According to mantle plume theory the Earth's interior cools partly by localized large vertical mass transport, causing extensive decompression melting. The Iceland melt anomaly is regarded as a typical example of a mantle plume. However, there are centers of Miocene to recent magmatism in the NorwegianGreenland Sea not easily explained by the plume theory. Here we present new data to document diffuse late Miocene magmatic underplating of older oceanic crust located mostly north of the Aegir Ridge, an extinct seafloor spreading axis in the Norway Basin. There is also a region with similar magmatism northeast of the presently spreading Kolbeinsey Ridge north of Iceland. Intraplate magmatism in these locations is not easily explained by local plume models, edge-driven convection, or by asthenosphere flow-lithosphere thickness interaction. On the basis of correlation between the magmatism and the active or extinct spreading ridges, we propose the mid-ocean ridge basalt-capture model, in which this magmatism can be understood through plume-spreading ridge interaction: The asthenosphere flow out from Iceland captures deeper, low-degree partially molten asthenospheric regions from underneath the spreading ridges and carry these across the terminating fracture zones, to subsequently underplate oceanic crust or to intrude and build seamounts. This model is similar to lithospheric cracking models for intraplate magmatism in requiring that low-degree partial melt can be retained in the asthenosphere over time but differ in that the magma is extracted by internal magma movement processes and not by external tectonic forces.

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Vesteris Seamount: An enigma in the Greenland Basin

Cited by 10 publications

References 8 publications

The Paleoceanographic History of the North Atlantic-Arctic Gateways: Synthesis of the Leg 151 Drilling Results

The Paleoceanographic History of the North Atlantic-Arctic Gateways: Synthesis of the Leg 151 Drilling Results

Prediction of sediment thickness in the Norwegian–Greenland Sea from gravity inversion

Neogene magmatism northeast of the Aegir and Kolbeinsey ridges, NE Atlantic: Spreading ridge–mantle plume interaction?

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