On a Phosphatic Chalk with Holaster planus at Lewes

Abstract

In 1891 I described before this Society a phosphatic chalk which occurred near the top of the Upper Chalk of Taplow, and resembled the deposits long known and worked in Belgium and the North of France, but not up to that time recognized in this country. Up to the present, in spite of much searching, no other occurrence of this rock has been recorded in England, but during the summer of 1895 Mr. John Rhodes, fossil collector to the Geological Survey, while engaged in collecting from the great chalk-pits near Lewes, noticed a thin band bearing a strong resemblance to the Taplow phosphatic chalk. At the request of the Director-General I visited the spot ,and made the following notes. The pit, which is marked on the 6–inch and 1–inch (new series) Ordinance maps as the Southerham Pit, lies on the south–western side of the high downs of Upper Chalk which overlook Lewes from the east. A somewhat marked syncline traverses the central part of these hills in an east–and–west direction. Thus Lewes, situated nearly on the synclinal axis, stands on Upper Chalk, but both to the north and south of the Downs the Middle and Lower Chalk emerge with southerly and northerly dips respectively. The Southerham Pit extends from the Middle to high up in the Upper Chalk, but the workings in the Middle Chalk have been abandoned and are partly obscured. A small bank, however, at the eastern end of the long line of limekilns affords a good view