GAVEY LOWER LIAS, GLOUCESTERSHIRE. 29 



whole of the carhoniferous rocks were disturbed and partially elevated, 

 with the remarkable peculiarity that the southern parts of both 

 districts have been squeezed up into parallel folds, from which the 

 northern parts are comparatively free. Thus the Culm-field of Devon- 

 shire and the southern side of the Belgian coal-districts are bent in 

 parallel folds, while the coal-field of Glamorgan and the northern 

 portion of the Belgian coal-fields are much less disturbed. The dis- 

 turbing forces are thus shown to have operated along a line on the 

 south of the two districts under consideration ; and on one end of 

 that line we have the elevation of the Ardennes, and on the other the 

 mica-schist of the Start Point and Bolt Head, the gneiss of the Ed- 

 dystone, and the serpentine of the Lizard Point. The line of eleva- 

 tion runs on the south side of the Devonian and carboniferous rocks 

 of the Boulonnais, which form a connecting link between the disturbed 

 districts of Belgium and Devonshire here referred to. 



I cannot conclude without acknowledging with thanks the assist- 

 ance which I have received from Mr. R. A. C. Austen, both during 

 our excursion in Belgium and the drawing up of this review. 



On the Railway Cuttings at the Mickleton Tunnel and at 

 Aston Magna, Gloucestershire. By G. E. Gavey, Esq., 

 C.E., F.G.S. 



[Plate I.] 



These sections occur on the Oxford, Worcester, and "Wolverhamp- 

 ton Railway. Mickleton Tunnel is situated near the north-eastern 

 extremity of the Cotteswold Hills. It passes through them in a 

 north and south direction, near the village of Mickleton ; the north 

 end opening out into the Vale of Evesham, and the southern into the 

 Vale of Moreton-in-the-Marsh. 



The Tunnel, which is about half a mile in length, has been driven 

 through the upper beds of the Lower Lias Shale ; and during its ex- 

 cavation, but more especially in the cuttings at each end of it, nume- 

 rous rare and beautiful fossils were discovered. 



The surface of the ground on the summit of the Tunnel is 490 feet 

 above the sea ; it is on a level with the Marlstone of the hills to the 

 east and west, and is composed of loamy siliceous gravel, sand*, 

 and red clays to a depth of 7^ feet, disposed in layers resting imme- 

 diately upon the upper beds of the Lower Lias Shale (see PI. I. 

 figs, i & 2). 



The following is the order of the beds from above downwards : — 



feet. in. feet. in. 



Vegetable soil about 9 



Loamy sand and pebbles from 5 to 15 



Fine loamy sand passing into coarse sand „ 5 6 



Gravel and clay „ 5 



Red clay with boulders of Marlstone ... ,, 2 



Loose shingly gravel „ 10 



Red clay with boulders of Marlstone ... „ 2 



20 



30 



6 



16 



15 



Lower Lias Shale more than 80 



* This siliceous sand contained about 30 per cent, of fine oolitic sand. 



