246 ARABLE LANDS OF THE OOLITE. 



in that part ofUie Nctth Riding of Yorkshire through which this formation 

 extends. 



The Oxford clay, which is by far the most important member of this forma- 

 tion, and forms the surface over by far tlie largest portion of the area occupied 

 by it — produces a close, heavy, compact clay soil, difficult to work, and which 

 is one of the most expensive of all the clays to cultivate. This is especially 

 the case in Bedford, Huntingdon, Northampton, and Lincoln, in which coun- 

 ties, neveriheless, a considerable extent of it is under the plough. In Wilts, 

 Oxford, and Gloucester, it is chiefly in pasture, and as over these districts it as- 

 sumes the character rather of a clayey loam, the herbage is thick and luxuriant. 

 The impervious nature of this clay has caused the stagnation of water upon 

 its lower lying portions, the consequent accumulation of vegetable matter, and 

 the formation of bogs. The extensive fens of Lincoln, Northampton, Hunt- 

 ingdon, Cambridge, and Norfolk, rest upon the Oxford clay. This tract of 

 fenny country is 70 miles in length, and about 10 in average breadth. When 

 drained and covered with the clay from beneath, it is capable of being converted 

 into a most productive soil. In Lincolnshire, there are about a million acres 

 of fen, which have their drainage into the Wash, about 50,000 of which are at 

 present in-eclaimable, on account of the state of the outlet. 



In the neighbourhood of the Kelloways rock the clay becomes more loamy 

 and less difficult to work. 



Both in Yorkshire and in the southern districts, the Oxford clay is found to 

 favour the growth of the oak, and hence it is often distinguished by the name 

 of tlie oak tree clay. 



^0°. Inferior Oolite. 600 ft. Thin, impuare, rubbly beds of shelly 



a Combrash, 30. lime-stone form the upper part of this 



b Forest Marble, 50. series. These rest upon alternate beds 



c Bradford Clay, 50. of oolitic shelly lime-stone and sand- 



d Bath Oolite, 130. stone, more or less calcareous, having 



g Fuller's Earth, 140. partings of clay ; these again upon beds 



/ Inferior Oolite, ) ^nn of blue marly clay, immediately under 



g Calcareous Sand, ] which are the thick beds of the Ught-co- 



loured oolite hme-stone of Bath. Be- 

 neath these follow other beds of blue 

 clay, with Fuller's earth, based upon 

 another oolitic lime-stone, which is fol- 

 lowed by slightly calcareous sands. 

 Extent. — This formation commences also at the south-westem extremity of 

 Dorset, and runs north-east, swelling out, here and there, and in Gloucester, 

 Oxford, and Northampton attaining a width of 15 to 20 miles. It occupies 

 nearly the whole of these three counties, covers almost the entire area of Rut- 

 land, a large portion of the north-east of Leicester, and tlien, in a narrow stripe, 

 stretches north through Lincoln, and disappears at the Humber. It appears 

 again in the North Riding of Yorkshire, skirting the outer edge of the middle 

 oolite, on the north of which it attains a breadth of 15 miles, and stretches 

 across, with little interruption, from near Thirsk to the North sea. A small 

 patch of it appears farther north, on the south-eastern coast of Sutherland, and 

 on the east and south of the Isle of Sky. 



Soil. — It will be understood from what has been already stated in reference 

 to other formations, that one wliich contains so many different rocks, as this 

 does, must also present many diversities of soil. Where the upper beds come 

 to the surface, the clay-partings give the character to tlie soil— fonning a calca- 

 reous clay, which, when dry or dredned, is of good quaUty. In other places it 

 forms a close adhesive clay, which is naturally almost sterile. The Bath oolite 

 weathers and crumbles readily. The soil upon it is thin, loose, and dry. The 

 rock is full of vertical fissures, which carrj- off the water and drain its surface. 



