- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
"On Orval, in the Isle of Rhum, Tertiary plateau lavas directly overlie the granophyre of the ring-complex. Judd considered that the Orval basalts rest unconformably upon an old land surface cut in the granophyre; but on the supposed existence of veining and metamorphism later workers, in particular Geikie and Harker, concluded that the granophyre had intruded the volcanic pile. The author's re-examination of the Orval rocks supports Judd's early interpretation."