94 
BED CRAG. 
deposited. At Sutton Coralline Crag rises to a height of about 
60 feet, and probably formed an island in the Red Crag sea, while 
close adjoining the Red Crag descends to the present sea-level. 
Mr. Dalton remarks that but little of the Red Crag east of the 
Deben is decalcified, its shells being retained even on the water¬ 
shed.* 
The Coralline Crag outlier at Sutton has already been men¬ 
tioned in the chapter describing that formation, but it still 
remains to notice the denudation that it underwent before the 
newer strata were deposited. It will be necessary for this purpose 
to make free use of Prof. Prestwich’s description, for he under¬ 
took a special survey of this area, and was able to examine 
sections now quite hidden or much obscured.t 
The reef or island of Coralline Crag is about a third of a mile 
across, and is overlapped on every side but the south by Red Crag, 
which abuts against a series of low vertical clifis or steep slopes. 
On the south the Coralline Crag may have been continuous 
till comparatively recently with the isolated mass at Ramsholt, for 
the narrow valley that now separates them is of modern date. 
The Ramsholt outKer is also overlapped by Red Crag, except 
towards the north, and perhaps to the north-west towards 
Waldringfield. The three sections now reproduced will illustrate 
better than any description the relation of the two deposits in the 
hill at Sutton.f 
Fia. 17. 
Section in the Bullock-yard Pit^ Sutton, 6iifeet above 
Low-Water Mark, 
Vertical scale of Figs. 17, 18, 19, about 12 feet to an inch. 
t. Floor of pit 31 feet above Low Water Mark. 
sb Upper shore-line, with blocks of Coralline Crag, flints, coprolites and shells. 
m. Seam of shells of My Ulus edulis, almost all with both valves. 
n. Bed of coprolites and large flints. 
s. Lower shore-line. 
* See also Geology of Ipswich, p. 67. 
f Quart. Journ. Geol. Soc., yoI. xxvii., pp. 116-119, 339-341, and pi. vi. (1871.) 
j Reproduced from Quart. Journ. Geol. Soc., vol. xxvii. p. 340, by the kindness 
of Prof. Prestwich and the Council of the Geological Society. 
