586 TRANSACTIONS OF SUB-SECTION B. 



2. The Drift Soils of Norfolk. By L. F. Newman. 



The central and eastern parts of Norfolk are almost completely covered with 

 drift, classified for mapping into three divisions by the Geological Survey 

 Department : — 



1. Boulder clay. 



2. Sands and gravel. 



3. Loam and brick-earth. 



The soils of each, especially the boulder clay, vary very much in character 

 and are extremely complicated, and small local differences occur even in soils 

 resulting from the same type of drift. The sand and gravel soils are very apt 

 to be cemented together by iron, forming a solid sheet of rock out of reach of 

 the plough. This holds the water up, and peaty patches may occur completely 

 altering the agricultural character of the land. In soil derived from the solid 

 chalk the lime is often completely dissolved, leaving the soil actually deficient 

 in lime. 



Woodward, in his memoir of the north Norfolk districts, says : ' Much of the 

 soil of the central and western parts is of a changeable and mixed character, from 

 the fact that the gravel and sand which originally extended over a very con- 

 siderable part of it have left indication of their former presence in the soil.' 



And again : ' The glacial drift of this area comprises almost every kind of 

 sedimentary and detrital formation, from chalk, mud, marl, clay, and loam, to 

 sand, gravel, and boulder gravel. The map distinguishes as far as possible 

 the marly and loamy beds from the sand and gravel; but at best this is a 

 lithological division, and it is difficult to be consistently accurate even in this 

 respect, for the beds give evidence of great disturbance and contortion, and also 

 of abrupt change in lithological character. ... It is not possible to separate 

 the gravel from the sand on the map. and even the boundary between the brick- 

 earth and the marl or boulder clay is only approximate.' 



The chalk outcrops along the north coast, and the resulting soils, which on 

 the hilly parts are only about four inches deep, grow the best barley in England. 

 In the valleys, however, the soil is deeper, probably due to a natural warping. 

 A correlation of these soils has yet to be made out. 



Nearly all the surface drift is deficient in lime, and wherever the marl or 

 chalky boulder clay is near the surface it has been dug into for the purpose of 

 carting it on to the land. Practically the whole country has for many years been 

 under the Norfolk or four-course system of farming, and this rather obscures 

 the natural capabilities of the land, hence the crop returns are less valuable as 

 an indication of soil character and fertility than is usually the case. 



In making a soil survey the first step is to make a preliminary tour, selecting 

 samples from various parts, and afterwards going again over the land and taking 

 a further series- to fill in details and complete the chain of results. 



Such a preliminary survey of the drift showed that the loams and brick-earths 

 had a strong likeness one to another. The percentages of the finer particles 

 decreased in each sample from east to west, which decrease was reflected in the 

 gradual lowering of the rentals of the farms lying along the lines of sampling. 



The sand and gravel also fell into lines of : — 



1. High and low stone percentages. 



2. High and low percentages of coarse sand, the great quantity of which 

 makes all the soils very open and inclined to 'bum.' 



Much of the gravel was under conifers or was common or waste land. 



The boulder clays showed very great variations, small areas showing similarity 

 of composition but differing markedly from other areas a mile or so away. It 

 would appear that a complete soil-map of the boulder clays would emphasise and 

 explain some of the differences alluded to in the Memoirs of the Geological 

 Survey. 



3. The Semiring or ' TearV Lauds ol Somerset. 

 By C. T. Gimingham, F.T.C. 



In certain districts of mid-Somerset the herbage of much of the pasture land 

 has the property of causing cattle feeding there to scour very seriously indeed 



