This report describes the results of excavations carried out in 1971 and 1972 by Mr R J Mercer for the Department of the Environment, or a previously undisturbed flint mine shaft at Grimes Graves in the Parish of Weeting, Norfolk. One Neolithic flint mine shaft, dating to around 1800bc, was totally excavated and a substantial surface area around the shaft examined. Much valuable information was subsequently recovered concerning the method of flint extraction and the social organisation of the mining community. A detailed account of the worked flint is published in volume II. The excavations at Grimes Graves also revealed evidence of a secondary phase of occupation of the site. During the Middle Bronze Age, a midden had accumulated in the surface of a second flint mine shaft - analysis of the considerable amount of midden debris produced a comprehensive picture of the economy and nature of this later occupation of around 1100bc. The volume contains important contributions by specialists on various topics including the pottery and the environmental evidence.