BRACKLESHAM BEDS, in geology, a series of clays and marls, with sandy and lignitic beds, in the Middle Eocene of the Hampshire Basin, England. They are well developed in the Isle of Wight and on the mainland opposite; and receive their name from their occurrence at Bracklesham in Sussex. The thickness of the deposit is from 100 to 400 ft. Fossil mollusca are abundant, and fossil fish are to be found, as well as the Palaeophis, a sea-snake. Nummulites and other foraminifera also occur. The Bracklesham Beds lie between the Barton Clay above and the Bournemouth Beds, Lower Bagshot, below. In the London Basin these beds are represented only by thin sandy clays In the Middle Bagshot group. In the Paris Basin the “Calcaire grossier” lies upon the same geological horizon.
See F. Dixon, Geology of Sussex (new ed., 1878); F. E. Edwards and S. V. Wood, “Monograph of Eocene Mollusca,” Palaeontographical Soc. vol. i. (1847 – 1877); “Geology of the Isle of Wight,” Mem. Geol. Survey (2nd ed., 1889); C. Reid, “The Geology of the Country around Southampton,” Mem. Geol. Survey (1902).