The scientists whose primary documented field is the general study of the solid earth's rocks, structure and history: James Hutton, Charles Lyell, William Smith, Adam Sedgwick, Roderick Murchison, Eduard Suess, John Wesley Powell, Grove Karl Gilbert, Harry Hess and Nicolas Steno among them. Belongs here: a scientist whose primary contribution is geological mapping, stratigraphic or structural interpretation, or a broad geological theory not specific to one of this atlas's other named specialties. Does not belong here: a scientist whose primary, documented contribution is a different named specialty even where their formal training or an early career stage touched general geology, held under that specialty instead.