112 
BED AND NORWICH CRAGS. 
Crag shells. Still further to the south-west Crag was again 
met with in a well at Hoxne E-ectory, and appears to have been 
60 or 70 feet thick ; possibly in the Hoxne well only the deposits 
immediately above the Chalk belong to the Crag, but the exact 
depth from which the fossils were obtained is not mentioned.* The 
only fossil recorded is Purpura lapillus (many specimens). Two 
miles away Chalk crops out, and no overlying Crag is visible. 
The sudden rise of the Chalk immediately west of Hoxne, coupled 
with the common occurrence of the rock-loving Purpura lapillus^ 
is suggestive of the existence in this neighbourhood of an old 
shore-line and buried Chalk cliff, against which the sheUy Norwich 
Crag is banked. The great thickness of the Drift makes it 
impossible, however, to trace this old coast, though each year 
additional borings penetrate to the Chalk, and before long we 
may be able to fix the original limits of the Norwich Crag sea. 
The Crag of the Waveney Valley is separated from the out¬ 
crops further north by a wide area occupied by later deposits, too 
thick to be often penetrated by wells. Where Crag reappears, 
the Chillesford Clay has become so impersistent and thin, and 
there is so marked a tendency for clay-seams to come on at 
various horizons, that Mr. H. B. Woodward, who examined in 
detail the typical area around Norwich, felt compelled to class 
together the whole of the deposits beneath the Lower Boulder 
Clay as Upper Crag or Norwich Crag Series. The following 
pages are mainly condensed from Mr. Woodward’s account.‘f 
The Upper Crag of Norfolk comprises a variable group of sands, 
pebbly gravels, and laminated clays, with occasional seams or 
patches of shells. Near Norwich and in the Bure Valley it has 
a general thickness of about 30 feet. The ordinary succession of 
the beds is as follows :— 
4. Buff false-bedded sand and red gravel, formed chiefly of flint 
pebbles, with also pebbles of quartz and quartzite, and 
ironstone nodules. Veins and seams of laminated clay 
occur, and the gravel is occasionally cemented into a con¬ 
glomerate or Iron-pan.” [This division has been called 
the Pebbly Sands and Pebble beds, the Bure Valley Beds, 
also the Westleton Beds.] 
3. l^aminated clay, with seams of sand and gravel; or clay and 
sand in thin layers rapidly alternating. [This division has 
been called the Chillesford Clay.] 
2. White and brown sand with pebbly gravel and ironstone 
nodules. [This division, including also No. 1, has been 
separated into an Upper or Chillesford Crag, and a Lower 
or Fluvio-inarine Crag.] 
1. Bed of unworn and rolled flints, called the Mammaliferous 
Stone-bed.” 
Chalk with flints. 
* Geology of Halesworth and Harlestou (^Memoirs of the Geological Survey'), 
p 38. 
f See also Geology of the Country around Norwich (^Memoirs of the Geological 
Survey), pp. 31-89, 
