:}04 Marh('i-(lar<h')\ Soi/s /ni<f Cropx 



(3) Variations in the depth of boulder clay cappings : e.g. boulder 

 clay on greensand is usually a sandy loam. 



(4) Variation in nuiterial deposited by different river systems: 

 e.g. old brown and now dark gravel soil formations. 



PART 11. 



Soil Formations — ilieir characleristic properties and agriculture. 



1. Oxford Clay Skkies. 



Dr lionney' states that the Neocomian deposits of this part of 

 Bedfordshire rest upon Oxford clay, the higher members of the Jurassic 

 clay series being absent. Reed* states that the Ampthill clay is 

 worked at Everton, but describes the lower greensand at Sandy as 

 resting on Oxford clay. Under these circumstances it is rather a 

 remarkable fact that soils taken from the extensive Oxford clay 

 plain between Sandy and Tempsford should resemble Kimeridge clay 

 soils closely in composition. 



F. W. Foreman' describes the Kimeridge clay soils which lie had 

 collected from a nund)er of widely separated districts as being dark 

 brown soils, devoid of lime. He says that the dark colour distinguishes 

 them quite readily from Oxford clay soils which are light coloured and 

 well supplied with lime. 



The present writer found that the Oxford clay soils in the district 

 investigated were invariably very dark brown in colour and resembled 

 the Kimeridge clay soils described by Foreman in an almost complete 

 absence of calcium carbonate. The following are the actual percentages 

 of calcium carboiiate found by Foreman compared with the percentages 

 found by the present writer. 



Foreman's results The irriter^s results 



Kimeridge clay* O.xford clay 



mean 2 analyses mean '.i analyses 

 CaCOo -18 407 



Soil from Soils from Snndy- 



Everton Tempsford plain 



•12 -27 



Whether this plain between Sandy and Tempsfoitl is Kimeridge 

 or Oxford clay is a matter for the geologist and not the atrriiulturist 



' Dr Bouney, Oeology of Cinnbridgenhire. 



* F. R. C. Reed, A Ilamllxmk to the Geology of Camltridgeshire. 



' F. W. Foreman, "Soils of Cambridgeshire." Journ. Agric. Set. vol. n. pt. 2. 



* Foreman {loc. cit.) describes one soil as containing 33 pei cent. CaCO„ but states 

 tlmt this soil is purely local in exlcnt and not characteristic of Kimeridge clay. 



