(I. W. Robinson 



371 



The average composition of five soils of this class is shown in the 

 general table. 



Calcium carbonate only occurred in one sample. 



Fine gravel ... 

 Coarse sand ... 

 Fine sand 



Silt 



Fine silt 



Clay 



Moisture 

 Organic matter 

 Calcium carbonate ... 



Nitrogen 



48 hours' digestion with HCl 



-049 — 



•084 — 



•188 — 



•198 — 



■162 



There are two classes of alluvial soil in North Wales, namely 

 (a) estuarine, and (b) fluviatile. 



(a) Estuarine Alluvium occurs in portions of estuaries or arms of 

 the sea which have been reclaimed by artificial or natural embank- 

 ments. The largest of these stretches is Malltraeth marsh in Anglesey 

 which has an area of several thousand acres and runs well into the centre 

 of that island. It was reclaimed by embankment and drainage over a 

 century ago. Unfortunately many of the drains are working very in- 

 efficiently and the land is at present waterlogged during the wet season. 

 If the drainage could be made efficient a large area of land would be 

 greatly increased in value. The other large area of reclaimed estuary 

 is at Portmadoc. This was reclaimed bv an embankment over a mile 



