It consists of alternating beds of ferruginous oolitic chert and fine-textured cherty carbonates. Birds include peregrine falcons, bald eagles, golden eagles, ferruginous hawks, and gray-crowned rosy finch. Those to the north are mostly shallow and ferruginous, brown or brownish red in colour. Birds taken by Prut wildcats include warblers, ferruginous duck, Eurasian coot, spotted crake, and gadwall. Bird species include pinyon jay, raven, quail, dove, ferruginous hawk, prairie falcon, and golden eagle. Winter visitors include black-bellied tern, red-crested pochard, ferruginous pochard and bar-headed goose. The stone consists of "ferruginous siltstone", and measures long and wide. Synonyms include ferruginous duricrust, hardpan and ironpan. Its geological composition comprises limestone capped with a very hard ferruginous layer of rock. Recent deposits are alluvial soils, high and low level laterites, and ferruginous conglomerates. These species have broadly similar breeding season diets, especially the ferruginous and red-tailed hawks. The first source of chalybeate (ferruginous) water was found in May 1705. The soils are ferruginous and more conducive to plant growth. Toxic chemicals have not been suggested as a significant threat to the ferruginous hawk. The name is a combination of "ferruginous" and "concrete".