Despite the evident importance of cone sheets in basalt volcanic systems, cone sheet complexes are still poorly understood and their origin is the subject of several competing hypotheses. We will apply paleo-magnetic techniques to test these hypotheses in two study areas: the Cuillin Hills of Skye (Scotland) in the roots of a major early-Tertiary basaltic volcano; and Kalfafellsdalur, a deeply eroded Quaternary spreading ridge in SE Iceland. We will use the NRM orientation to determine whether the centrally-inclined character of the sheet-intrusions is due to post-intrusion tilting. We will determine the magma-flow direction by magnetic susceptibility anisotropy, and we will estimate thermal gradients in country rock adjacent to sheets by paleomagnetism.
