Collection of rock cores extracted during drilling operations by Great Northern Paper for mineral exploration in northern Maine. Drilling occurred in townships: T1R12, T2R9, T3R11, T3R15, T7R15, T8R9, T9R10, T10R7, T10R9, T10R10, T11R9, T15R9. Please contact the Maine Geological Survey to discuss access to the collection.