131 
CHAPTER yill. 
CHILLESFORD CLAY AND WEYBOURN CRAG. 
In the last Chapter the Pliocene strata were followed north- 
ward, until Red Crag gave place to Norwich Crag, and that in 
turn was overlapped by Weybourn Crag. We will now return to 
the southern portion of the district and notice the sections of the 
overlying Ghillesford Clay—many of them already incidentally 
alluded to in previous Chapters. The Chillesford Clay is here 
treated of apart from the underlying beds, because it points to 
the commencement of somewhat different conditions. The de¬ 
position of shelly Crag gave place to that of strata consisting 
largely of laminated micaceous clay, sometimes with lignite and 
sometimes with bones of stranded cetaceans, but seldom containing 
mollusca. These laminated clays seem to indicate more estuarine 
conditions and shoaler water, for it is under such circumstances 
that thin alternations of sand and clay are laid down, and the 
skeletons of whales also point to muddy shoals, among which the 
animals became entangled and stranded. 
The Weybourn Crag is treated of in the present Chapter, for 
recent observations seem to indicate that this deposit may be 
merely a sandy modification of the Chillesford Olay, coming on as 
the strata are traced beyond the limits of the sheltered estuary to 
an area where marine mollusca could flourish. It must have 
been laid down in shallow water, for though lying at a lower level 
than the Crag at Norwich it indicates quite as littoral conditions. 
The southernmost outlier is found at Walton Naze, where the 
carbonaceous clay overlying the Red Crag has been identified 
with the Chillesford Clay by Prof. Prestwich and by S. V. Wood, 
jun. Mr. Whitaker, whose section has^ already been quoted in 
Chapter YI. (p. 83), follows their determination, though with 
some doubt; but after a re-examination of the cliff I cannot help 
feeling uncertain whether the clays and gravels do not represent 
rather the Cromer Forest-bed. A section about 12 chains south 
of Walton Tower showed in 1886 :— 
Feet. 
9. Soil li 
'8. G-ravel of unworn flint, with abundance of "I 
flint, quartz, and quartzite pebbles—no y 5 
Boulder Clay stones observed - - J 
7. Bedded loam, with scattered angular flints and 1 -i ^ o 
pebbles - - - - .|lto3 
6. Gravelly sand ----- i 
5. Stiffer loam (base blue clay) - - - Ih 
4. Black carbonaceous loam with decayed wood \ ^ 
and obscure vegetable impressions - - J 
3. Gravel of unworn and worn flints, quartz, and \ i 
quartzite (as No. 8) - - - - J 
2. Red sand (decalcified Crag) - - - 6 
1. London Clav. 
Chillesford 
Clay ? (or ■< 
Forest-bed). 
