746 
VEGETATION SURVEY OF NORFOLK. 
A pit on Royal Hill, Ringland, showed chalky boulder clay 
with patches of flint pebbles and red sand. At Messrs. Lacey 
and Lincoln’s brickyard in Newton Flotman the section in 
1911 showed 15 feet of chalky boulder clay, which has been 
worked for another 10 feet. Of boulders not referred to in 
the Geological Survey Memoirs we noted one of ferruginous 
sandstone containing two cubic feet near the site of Mountjoy 
Priory, Haveringland ; one of flint 2 x 1 ft. in a pit S.W. 
of Weston, and one about 9 X 4 X 3 ft. in the stableyard 
at Mortem Hall, brought from Honingham brecks by the late 
Mr. Berney (d. 1887). Above the boulder clay in some parts 
of the district is loam, as at Alderford Common (where it was 
formerly used for brick-making) and at Great Witchingham, 
where patches of chalky boulder clay occur in its lower part. 
Much more important in its effect on the vegetation is the 
plateau sand and gravel which tops the boulder clay, and caps 
many of the hills and much of the higher ground. The chalky 
boulder clay, plateau sand and gravel, and the brick earths, 
undoubtedly explain to a large extent the differing plant 
associations. In places this gravel is 21 ft. in thickness. In 
the valley of the Wensum there is a considerable quantity of 
valley gravel in banks or terraces, first on one side of the river 
then on the other, as at Great Witchingham, Attlebridge, 
Costessey, Drayton, and also in the tributary valleys of the 
Bure below Spixworth Bridge. The alluvium varies in different 
localities. At Morton a section noted when the railway was 
being made gave 4 ft. of peat, 8 ft. of black silt with fresh- 
water shells, hazel nuts, fir cones, and wood, and 4 ft. of grey 
sand and silt. A lower jaw of Cervus and a large skull of 
Bos were found. 
Arable. 
The greater portion of the area consists of arable land, cropped 
in the usual Norfolk four-course rotation. The boulder clay 
districts are good wheat land, beans forming one of the main 
crops, while the lighter soils are better for barley. The only 
