Note on the gravel deposit from which the Piltdown skull was obtained

Abstract

The age of the Piltdown skull has long been a subject of intermittent controversy and it is a question which can only be determined from palaeontological data or other evidence inherent in the fossil itself, such as that provided by fluorine fixation; details of river-terrace forms and levels as related to the present-day thalweg of the River Ouse, and of materials comprising the gravel in which the skull was found, offer little assistance. In the literature on the subject some misunderstanding has arisen as to the height of the gravel deposit in which the skull was found relative to the present-day River Ouse; height above the river having to some extent been used to date the fossil. According to levels taken from the six-inch scale Ordnance Survey map, Sussex 40 NE., the 100-foot contour above Ordnance Datum cuts the surface of the gravel spread, the highest part of which lies about 103 feet O.D. while the lowest part is about 97 feet O.D. The nearest part of the River Ouse, at Gold Bridge, is between 45 and 50 feet O.D. Thus the terrace is is about 50–55 feet above the nearest part of the river. Dawson (1913, p. 119), however, stated that the terrace lies on a plateau above the 100-foot contour, with an average height of about 120 feet above O.D.; a statement true of the plateau, but not of the gravel terrace, which is the thing that matters. Again, he gave the height of the gravel spread above