Lower Chalk 31 



The beds immediately above the Burwell Rock have many 

 features in common with that rock but are less compact and 

 contain far less detrital matter. At Cherryhinton the first 

 twenty feet is considered unfit for lime-burning, but near 

 Fulbourn Asylum and at Swaffham it is quarried for that 

 purpose. Pits opened in these beds are generally worked fur 

 clunch or wattle making. We may mention those of Newton, 

 Eversden, Haslingfield, and Shelford. The upper fifty feet 

 of the sitbglobosus zone is much whiter than any of the 

 beds below it, and is a hard homogeneous chalk in which 

 the stratification is not at all obvious. Being very pure and 

 yet quite free from flints it is locally much used in the making 

 of lime for building, and the sections at Cherryhinton are the 

 best in the district. 



The great pit of Cherryhinton is situated at the north end 

 of a spur of the Gog Magog Hills and, having been worked 

 well into the hill, it exhibits in continuous series all the 

 members of the Lower Chalk. 



The older north eastern end of the pit is no longer worked, 

 but the upper beds of Burwell Rock and the overlying clunch 

 beds can still be seen in the deep hole on the right of the 

 Cherryhinton entrance. Fossils may be collected there, the 

 commonest being Rhynchonella Martini, Terebratula biplicata, 

 and the lamellibranchs Inoceramus, Pecten, and Lima. 



Lime-burning from the rest of the quarry is proceeding 

 vigorously, but the beds are poor in fossils and it is rare to 

 meet with anything determinable. The men working in the 

 lower part of the pit, however, sometimes come across specimens 

 of a few species and save all they can get. The most usual 

 are Terebratula semiglobosa, and beautiful specimens of the 

 zone fossil Holaster subglobosus. Sharks' teeth and Pecten 

 orbicularis are not rare, and the big Pecten Beaveri occurs. 

 The whole recorded fauna does not exceed a score of species. 



The higher part of the pit seems to contain no fossils, but 

 shows very clearly the peculiar curved jointing characteristic 



