GEOLOGY 



seen is 25-30 feet up to the base of the Triassic sandstone. From this 

 spot it may be traced with the same character to the west side of 

 Bulwell and Hucknall Torkard, by the lake at Newstead and on the 

 other side of the Triassic ridge to the brickyard near Kirkby station. 

 Further on it forms the flanks of a hill between Mansfield and Skegby. 



After an interval, north of Mansfield where the Trias overlaps and 

 conceals it, a new development commences beyond Cuckney, where a 

 broad expanse of it occupies the surface which culminates at Woodhouse 

 Hill. Here is seen in a lane-section 30-40 feet of red sandstone in thick 

 beds alternating with clay near the centre. On this rising ground there 

 is a valley in which the Magnesian Limestone has been quarried beneath 

 these red sandstones ; over these come clays and over these again 

 comes a higher limestone occupying the higher ground (Aveline). Thus 

 the clays and sandstones are here included between two limestones. A 

 little further north the red sandstone gives the names to Ratcliff and 

 Red Hill. It much resembles the Trias sandstone, but it passes as 

 before beneath the marls and limestone. In the Shireoaks sinking 

 thirteen alternations of sand and clay in 46 feet were passed through 

 between two limestones, but on the east of the county 133 feet with 

 gypsum are recorded at Southcar and 150 feet at South Scarle in the 

 same relative position. 



THE UPPER LIMESTONES. These have been already noticed as cap- 

 ping the marls in places, and in the extreme north they come on in 

 force and form an essential feature in the south Yorkshire type of 

 Permian. The series consists of i 20 feet of thin-bedded limestones of a 

 quite different character from that of the Magnesian Limestone. They 

 were called ' Brotherton Beds ' by Professor Sedgwick. They are 

 described by Mr. Kirkby 1 as ' usually hard and compact and of a yellow 

 or grey colour ; the surface planes are generally a little apart and often 

 coated with red, green, or purple clays.' They contain very little mag- 

 nesia, so that the term magnesian should be restricted to the lower lime- 

 stones. They are much jointed and have the joint faces covered with 

 dendritic markings. They are first seen in force just north of Shireoaks, 

 round Ramoth-Gilead, and continue to the many quarries round Carlton 

 and Oldcoates, where fossils abound. Those recorded are Myalina baus- 

 manni (M. squamosus, Sow.), Schizodus truncatus and S. schlotheimi. 



The Upper Limestone is found again in the deep borings in the 

 east of the county, that at Southcar showing 53 feet of grey limestone in 

 one mass between two series of marls and that at South Scarle showing 

 43! feet in the same position. It does not appear therefore to be thick- 

 ening in this direction. 



THE UPPER MARLS. In certain places in the north of the county, 

 viz. on Whincommon, north-east of Oldcoates and near Carlton, the 

 Geological Survey 3 record the occurrence of red and variegated marls, 

 without intermixed sandstone, above the Upper Limestones. These are 



1 Quart. Journ. Geol. Sue. vol. xvii. 

 8 Geol. Survey Mem. sheet 82, N.E. 



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