41 2 
MR. H. B. WOODWARD ON THE SOILS AND SUBSOILS OF NORFOLK. 
the screen of soil, the junction with the grey and green marls which 
form a passage into the Rhmtic Beds. On the gently sloping 
uplands we can follow the junctions of the White Lias of the 
Upper Rhaetic Beds with the overlying Blue Lower Lias across 
many au arable tract where fragments of the well-known Landscape 
Marble and of White and Blue Lias are turned up by the plough. 
Again in Dorset, the silicious sands of the Upper Green Sand and 
the calcareous sands of the Lower Oolites impart distinct characters 
to the soil and vegetation. In those regions of course there are 
many exceptions where the soil has been shifted down the slopes, 
but there has not been that overspread of Drift which in the 
Eastern Counties was afterwards in places largely washed away so 
that in some areas the remnants exist merely in the soil, and cannot 
be distinguished on a geological map. 
Expert knowledge seems, therefore, needful to interpret maps 
whereon the superficial extent occupied by the many different 
geological formations is shewn irrespective of the carpet of soil. 
The question has often arisen, can maps be made for agricultural 
purposes to show the distribution of soils. No one, so far as 
I know, has attempted this in detail. The little maps published in 
the ‘Journal of the Royal Agricultural Society’ have been subsoil 
rather than soil maps. Maps on a scale of at least six inches to 
a mile would be necessary in order to admit of the variations of 
soil being indicated in reference to every field, but such a map 
comes hardly within the reach of practical geology. 
The natural divisions of soils are those based on their litho- 
logical or mineral character, using the term in a general sense 
to include gravelly, sandy, loamy, clayey, marly, brashy, and peaty 
soils. All these shade one into the other, so that we have gravelly 
clays and stony marls, peaty sands, sandy soils with gravelly 
patches here and there, and so on. 
On this account, as soils merge laterally, it would be far more 
difficult to draw any boundary-lines on maps to separate them, than 
it is to draw lines separating the subsoils which, whether in 
uniform or variable masses, overlie one another. 
Trimmer, in his paper of 1850, suggested a notation which has 
been followed in some of the German agricultural maps. Thus, 
/ ur 
if f indicates fine sandy loam, g gravel, and s sand, g 2' placed 
s 4' + 
