A hotspot model for Iceland and the Vøring Plateau

Abstract

The proximity of a hotspot to a spreading center may result in the channeling of atmosphere to the section of rise crest closest to the hotspot. This produces more basalt and thicker crust at these locations, thus forming a plateau over time. The geometric constraints of such a model predict a unique orientation, location, and age progression for a plateau formed by this mechanism. The hotspot will channel material to the closest part of the rise; therefore the orientation of the plateau will differ from that of a hotspot track by the component of absolute motion perpendicular to the rise axis. The plateau will be symmetric with respect to the location of the rise axis at the time of formation. Also, the age progression of the plateau will be contemporaneous with the age of formation of the seafloor on either side because the plateau is seafloor, just with thicker crust. A set of reconstructions based upon magnetic isochrones and a fixed hotspot reference frame is presented for the Norwegian‐Greenland Sea as a means of evaluating the model's predictions. By locating the Iceland hotspot, reconstructing the relative positions of the Greenland and European plates, and then assuming material would be channeled from the hotspot to the closest section of the rise crest, we can trace the tectonic evolution of the Greenland‐Faeroe and Vøring plateaus. The model is able to locate the plateaus, explain their orientations, and predict an age progression that satisfies observed age determinations. The analysis demonstrates that both plateaus could have been formed by the Iceland hotspot with the Greenland‐Faeroe Plateau being in effect a continuation of the Vøring Plateau, which was cut off due to transform motion between the northern and southern spreading centers.

The origin of the asymmetry in the Iceland hotspot along the Mid-Atlantic Ridge from continental breakup to present-day

“…This simplification is consistent with the Greenland-Iceland and Faeroe-Iceland volcanic ridges, representing the hotspot tracks on both plates, with the hotspot being very near or at the ridge since continental breakup (Vink, 1984;White, 1988White, , 1997Wilson, 1973).…”

A gravity and magnetic anomaly study of the extinct Aegir Ridge, Norwegian Sea

“…This may successfully explain the pattern of regional asymmetry observed north of Iceland, where the North American plate has moved more rapidly, while the Eurasian plate has been relatively stationary. However, Vogt [1986c] [Vink, 1984]. If Iceland hotspot activities had influenced the formation of the Aegir Ridge, the overall physiography should be similar to that formed on the Mid-Atlantic Ridge near presentday hotspots, e.g., near Iceland or the Azores.…”

Volcanism in Iceland in historical time: Volcano types, eruption styles and eruptive history

“…The construction of the Iceland basalt plateau is by most considered to be the product of an interaction between a spreading plate boundary and a mantle plume (e.g. Vink, 1984;White et al, 1995;Bjarnason et al, 1996;Wolfe et al, 1997;Allen et al, 1999). The construction is thought to have begun about 24 million years ago (e.g.…”

“…The surface expressions of this interaction are the neovolcanic zones; a discrete 15-50 km wide belts of active faulting and volcanism (e.g. Saemundsson, 1979;Jóhannesson, 1980;Vink, 1984;Óskarsson et al, 1985;Hardarson et al, 1997;Fig. 1.…”