264 Further Studies on the Soils of North Wales 



consists of material Generally external to the district but in all cases 

 originating from rocks lying to north or north-east. The drift soils 

 described in the present paper are derived from this external drift. 

 It may be added that in Anglesey there are drift deposits formed by the 

 northern glacier which consist almost entirely of local schistose material, 

 probably transported as ground moraine from no great distance. The 

 soils derived in this way were grouped and studied with the Palaeozoic 

 soils. The drift soils of this paper consist mainly of material derived 

 from localities other than those in which they occur. In west Carnarvon- 

 shire, however, there is an admi.\tiu-e of local material which makes 

 classification rather difficult. In fact the drifts of that area show all 

 gradations between soils consisting wholly of external material and 

 soils consisting of local material. The typical Northern Drift soil can 

 bo readily recognized by the nature of its sand fractions, which consist 

 of rounded quartz grains, while the local material is represented by 

 angular or lenticular fragments of igneous or shaly rocks. 



The boundary between northern and local drift is not always well 

 defined. In fact, large areas have been subjected to both glaciations 

 and northern and local drift may be found in vertical succession. 

 Denudation by weathering has led to the surface soil being a mixture 

 of both kinds of drift. 



The coastal drift plain of the northern coast of Carnarvonshire and 

 Denbighshire extended much farther north in former times. The vast 

 sand stretches at the northern end of the Menai straits are most probably 

 the remains of former land, for there are no sand bearing rivers which 

 could account for such exteneive deposits. This hypothesis, it may be 

 added, is in accord with Welsh traditions. 



General. 



The results of the analyses are summarised in Table I. In the former 

 paper, it was possible to give some idea of the dispersion of the results 

 in two of the types examined. The soils studied in the present paper 

 do not lend themselves to such treatment. Each type is to be regarded 

 rather as a series varying between limits: one type frequently shades 

 off into another, so that it is not always easy to determine to what 

 type or class a soil should be referred. P'or example, in the case of the 

 soil type described as the West Carnarvonshire Light Loam, examples 

 are found which genetically and intrinsically approach the Carnarvon- 

 shire Stony Loam described in the former paper. The fact that the 

 area examined in this paper is almost entirely covered with drift ex- 



