Vol. 67.] PERMIAN TO THE TRIAS IN NOTTINGHAMSHIRE. 85 



that form the long spur of high ground stretching southwards from 

 the Robin Hood's Hills, through Annesley Park, to near Hucknall 

 Torkard. 



At Bulwell Spring, east of the River Leen, a 9-foot section of 

 the passage-bed shows very well the lenticular and inconstant 

 character of the strata. 



Wilson T states that at Bestwood the passage-beds replace all but 

 8 or 10 feet of the Lower Mottled Sandstone. 



During the construction of the Bulwell Viaduct for the Great 

 Central Railway, sections seen in the excavations were noted by 

 Mr. Allen, 2 engineer to the line, and by J. Shipman. The upper 

 part of the Marl was sandy, though the bottom 8 feet of the section 

 showed nothing but solid marl. 



The best exposures, however, of the Permian Marl and Lower 

 Mottled Sandstone, in this area, are in the outliers which occur 

 west of the Leen. Thus the Marl is seen at Bulwell Quarries, 

 where it rests with a sharp junction on the Magnesian Limestone, 

 but appears to pass upwards into Bunter. Farther north, 550 

 yards south-east of Broomhill, Bunter of very marly character is 

 seen in a sand-pit, and here an actual lateral passage of marl into 

 sandrock can be traced. Another small outlier at Butler's Hill 

 has been cut through by the Great Northern and Midland Rail- 

 ways, showing, obscurely, very marly sandrock resting upon a floor 

 of (Permian) marl. 



Details of other sections have been already published, 3 and need 

 not, therefore, be described again. 



A curious feature of the Magnesian Limestone, which seems 

 worthy of more notice than it has yet received, 4 is the presence of 

 very sharp anticlinal and monoclinal folds, which form ridges of a 

 distinctly artificial appearance. Aveline noticed some of them, and 

 marked them on the Survey map (Old Series) with the anticlinal 

 symbol. They are, however, fairly numerous, their axes lying 

 in either a north-westerly or a north-easterly direction ; and it 

 has been found, by examining the colliery plans, that in several 

 cases the ridge at the surface indicates a fault in the Coal Measures 

 below. The structure of the ridges may be seen in several quarries 

 and on the Great Central Railway near Hucknall Torkard, where 

 the line cuts obliquely through the main ridge. The flaggy lime- 

 stones, which usually lie almost horizontally, are seen to rise 

 suddenly into an anticline (or sometimes a monocline) having a dip 

 of 20°, 40°, or even more. The base of the anticline is often only 

 some 20 yards wide, and the height of the ridge may be as many 

 feet. The ridges are not continuous for any distance, but are made 

 up of elongated domes arranged along a straight line, or sometimes 

 slightly en echelon. Moreover, mapping has shown that a 

 fault in the Coal Measures below may extend much farther than 



1 E. Wilson, 1876, p. 534. 



2 W. Gibson & others, 1908, p. 109. 



3 Ibid. pp. 106-10 & 129-30 ; also G. W. Lamplugh & others, 1908, pp. 27- 

 8 & 31-34. 



4 W. Gibson & others, 1908, p. 108. 



