522 



THE WONDERS OF GEOLOGY. Lect. V. 



borders of Nottingham and Lincoln, to Barrow-upon-Soar ; 

 whence it continues, accompanying the escarpment of the 

 inferior and great oolite, through Nottingham, Warwick, 

 and Gloucester. Its whole course, to within a few miles 

 south of Gloucester, is remarkably regular, presenting an 

 average breadth of about six miles, bounded on the south- 

 west by the Oolite, and on the north-west by the Red 

 marl, which will hereafter be described. Beyond Glou- 

 cester, its range becomes intricate ; its eastern limit accom- 

 panies the oolite through Somersetshire to Lyme Regis ; 

 but the western is very irregular, feathering in and out 

 among the coal-fields, which occur towards the estuary of 

 the Severn, and the upper part of the Bristol Channel, 

 Gloucestershire, Somersetshire, Monmouthshire, and Gla- 

 morganshire, and attended with numerous outlying or de- 

 tached masses. To render the course and position of the 

 Lias in this part of England intelligible, it is necessary to 



South of Malmcsbury. 



Lign. 118.— Section from south of Malmesbury through the Mendip 

 Hills. 



1. Mountain limestone. 2. Millstone grit. 3. Triassic strata. 4. Lias. 



5. Inferior Oolite. 6. Great Oolite. 7. Oxford clay. 



(From the Geology of England and Wales.*) 



state, that this district is occupied by three great basins of 

 the coal formation, encircled by the underlying and sub- 

 jacent limestones, and Devonian sandstones ; one of which 

 is shown in the annexed section. 



* The inclination of the strata is very much exaggerated in this 

 diagram, in consequence of the difference in the horizontal and ver- 

 tical scales, necessarily adopted to comprise the section in a small 

 space. 



