The Norfolk Crag deposits bear a considerable resemblance to those of Suffolk, consisting, like the latter, of a variable group of shallow-water marine sands, pebbly gravels, and laminated clays, with occasional seams or patches of shells.

The chief differences appear to be:—

(1) The progressive lowering of temperature observed as the Suffolk beds are traced from south to north has continued still further, culminating in the “Tellina balthica” aspect of the Weybourne Crag.

(2) In every known exposure the Norfolk Crag rests directly on the chalk, not on a Tertiary clay.

(3) The Norfolk “Stone Bed” ıs much more closely packed with flints than the corresponding “Detritus Bed” of Suffolk.

(4) The “coprolitic” content is much less.

(5) The mammalian fauna presents some differences from that of the Detritus Bed.

(6) It is possible the latter deposit is of a greater age than the former.

The attention of students of Prehistory was first called to the Crag deposits by Reid Moir's discovery in 1909 of apparently humanly worked flints in the Detritus Bed at Ipswich. This discovery, though supported by W. G. Clarke's researches at Norwich, was hotly contested, and gave rise to one of the most prolonged and embittered controversies of recent times, the echoes of which, however, have by now almost died away. At the present time every outstanding authority, who has studied the deposits in person, has endorsed Reid Moir's views.