The Tharsis region of Mars is characterized by large volcanic and tectonic centres that have been active throughout Martian geological history, including distinct sets of graben that extend radially for distances of hundreds to thousands of kilometres. Formation of these graben has been attributed to crustal extension and/or dyke propagation. Physical analogue models using layered sand and liquid paraffin wax were constructed to test the magnitude and style of deformation in the host rock associated with dyke injection. A variety of igneous morphologies was produced, including dykes and plugs. Results suggest that, in the absence of pre-existing faults, vertical dykes do not produce significant deformation in the surrounding rock. Deformation associated with other magmatic intrusions produced primarily contractional features rather than extensional features, similar to previous numerical studies and terrestrial field investigations.