Farming of Lincolnshire. 



269 



lieveJ, has never yet been sunk through, and spread out to a 

 great breadth between the Wolds and the Cliff and Witham Fens. 

 A line taken at right angles to its course is about 15 miles in the 

 widest part, probably its maximum of superficial extent in this 

 kingdom. This tract is extremely low, scarcely exceeding in 

 height the fens which cover its other portion. It is to a large 

 extent hidden beneath thick beds of drift, principally the white 

 clay called " chalk breccia." The clay itself is generally barren 

 and intractable, a heavy outlay of capital being necessary in order 

 to farm upon it with success. 



The cretaceous system of rocks exhibits an arrangement dif- 

 ferent from that which has been observed in other parts of Eng- 

 land, particularly as regards the green sand formation. The 

 following is the order of the beds : — 



Name of 

 Formation. 



Thickness iu 

 Yards. 



By what Beds represented. 



Nature of the Rock. 









Soft chalk, with 

 flints in layers. 



Chalk. . 1 



100 1 



Red chalk. 



Quartzose ferruginous pebbly 

 sand. 



Calcareous clay, containing 

 beds and concretions of oolitic 

 limestone. 



2 to 4 

 6 to 10 



12 to 14 



Harder chalk. 1 



Green-sand 



Considerably 



Granular quartzose sandstone 





thicker than 



and sand, varying from dark 







the two 



brown to light grey, and con- 

 taining shells. 







former beds 







of sand and 







I 



clay. 







The Green sand first appears upon the surface near the town 

 of Brigg, and thence continues southwards in a narrow strip in 

 front of the chalk. West of Caistor, and extending towards 

 Market Rasen, it is a wdde flat moor of sand, wet with the brooks 

 from the Wold hills. The surface varies from a red gaulty 

 sand to a black peaty sand, altering at almost every chain. Un- 

 der grass it is dark with vegetable matter from the decaying root- 

 fibres ; when ploughed, it is a loose red or black earth, the fur- 

 row-slices grey with veins of white sand. Underneath, 4 to 6 or 

 8 inches of the surface-soil is a rusty sand, sometimes cohering 

 together like soft sandstone. In Nettleton Common this is about 

 30 feet in depth; and the whole reclines upon blue clay, which 

 dips under it from the west. Some parts of it are light blowing 

 yellow sand, drifting out of one field and forming a hillock in 

 another. It is probably by the agency of wind, and perhaps also 

 of water, that the surface generally has become so level, much of 



