Being sited between two river mouths, the city has little natural exposure of bedrock. This leaves local geologists in a slight quandary: despite the high concentration of geoscientists in the area (courtesy of the oil industry), there is only a vague understanding of what underlies the city. To the south side of the city, coastal cliffs expose high-grade metamorphic rocks of the Grampian Group; to the southwest and west are extensive granites intruded into similar high-grade schists; to the north the metamorphics are intruded by gabbroic complexes instead.