The proximity of a hotspot to a spreading center may result in the channeling of asthenosphere 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 isochrons and a fixed hotspot reference frame is presented for the Norweigian-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 Voring 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 Voring Plateau, which was cut off due to transform motion between the northern and southern spreading centers. |