BARTON BEDS, in geology, the name given to a series of softish grey and brown clays, with layers of sand, of Upper Eocene age, which are found in the Hampshire Tertiary basin, where they are particularly well exposed in the cliffs of Barton, Hordwell, and in the Isle of Wight. Above the highly fossiliferous Barton Clay there is a sandy series with few fossils; these are the Headon Hill or Barton Sands. Either of these names is preferable to the term “Upper Bagshot Beds,” which has been applied to these sands. The Barton Beds are absent from the London basin, and the Upper Bagshot Sands of that area are probably at a lower horizon than the Barton Sands. The term “Bartonien” was introduced by Mayer-Eymar in 1857 for the continental equivalents of the series.
| Hampshire basin and Isle of Wight. |
Paris Basin. | ||||
| Barton Sands Barton Clay |
140–200 ft. 162–255 ft. |
Bartonien | Limestone of St. Ouen. Sands of Beauchamp (sables moyen). | ||
Fusus longaevus, Volutilithes luctatrix, Ostrea gigantea, Pectunculus (Glycimeris) deleta are characteristic fossils; fishes (Lamna, Arius, &c.) and a crocodile (Diplocynodon) are also found in the Barton Clay. The sands are very pure and are used in glass making.
See “Geology of the Isle of Wight,” Mem. Geol. Survey (2nd ed., 1889); “The Geology of the Country around Southampton,” Mem. Geol. Survey (1902). (J. A. H.)