SOILS AND AGRICULTURE OF NORFOLK. 
355 
from 2 to 20 feet in thickness, which lies over the chalk and 
gives rise to the bracken-covered commons so characteristic 
of the scenery of the district. 
The solid strata exposed in Norfolk are : — 
Crag . . . . Pliocene 
Chalk . . . . Cretaceous 
Gault . . . . ,, 
Greensand . . . . ,, 
Kimeridgian . . Jurassic 
The surface deposits (drift) are as follows : — 
Alluvium 
Blowing sand 
Glacial sand and gravel 
Stony loam and brickearth 
Boulder clay 
Old river gravels 
The dip of the beds is eastward and at a very small angle 
with the horizon. The shallow Pliocene deposits extending 
from as far east as Wymondham and Cawston to the sea, 
completely cover the western side of the county. The 
chalk forms the whole of the central boss of Norfolk — 
“ High Norfolk,” as it is locally termed — with the gault and 
greensand outstanding along its western edge. The jurassic 
clay which forms the bed of the Fenland is only exposed in 
a narrow strip some four miles wide extending from Southery 
to Lynn. 
The drift is of great complexity, and has received consider- 
able attention from geologists, Norfolk surface deposits having 
been mapped by Messrs. F. W. Harmer, Searlcs Wood, and 
H. B. Woodward. H.M. Geological Survey maps published 
| and 1 inch maps of the county, but 6 inch maps are needed 
for the detail demanded by a soil map. As is well known by 
farmers, lithological changes occur in any field, and an inch 
map can only show the changes over comparatively large 
