404 William Hill — The Upper Chalk of Lincolnshire. 



VI. — Note on the Upper Chalk of Lincolnshire. 

 By William Hill, F.G.S. 



IN the Geology of East Lincolnsliire, a memoir of the Greological 

 Survey published in 1889, the whole of the flint-bearing Chalk 

 of that county above the Melbourn Rock was referred to as Middle 

 Chalk, and no horizon was found which could be regarded as the 

 equivalent of the zone of Rolaster -planus, or the Chalk Eock of 

 the Midland counties. 



As our knowledge of the fossils of the Upper Chalk increased, 

 the occurrence of Infulaster excentricus, Uchinoconus globulus, and 

 Bhynchonella limbata, which had been collected by Mr. Rhodes 

 from a quarry at Acthorpe, near Louth, suggested to Mr. Jukes- 

 Browne that there might after all be some part of the Upper Chalk 

 exposed in north-east Lincolnshire ; and for the purpose of obtaining 

 evidence on this point I made two visits to this locality in 1897 

 and 1898, and was fortunately enabled to establish the fact of its 

 existence in this county. The zone of Rolaster planus was well 

 marked in a quarry near Boswell Farm, half a mile north-west 

 of North Elkington, about three miles north-west of Louth. The 

 section here was as follows : — 



Clayey gravel and chalk rubble 



White chalk with three layers of large flat flints and some scattered 



flint nodules. Echinocorys scutatus, Micr aster Leskei 

 Firm white chalk, JSficrasiJi??' Z«s^"ei 

 A thick continuous floor of flint 

 White chalk, rather harder, ynth Solaster pla9im, Micraster Leskei, 



and Echinocorys scutatus 

 A thick layer of intermingled chalk and flint 

 Firm white chalk with a layer of large flat flints (partly obscured) 

 Harder chalk with two layers of intermingled chalk and flint 



31 4 



The typical fossils of the zone occurred in the upper part of the 

 section only ; the specimens of Micraster Zeshei were large ones. 



Quarries to the eastward between Elkington and Fotherby , and again 

 near North Ormsby, expose another set of beds, which must be very 

 nearly on the same horizon as those at Boswell, and are different from 

 any seen to the south of Louth. These beds have been described 

 in the memoir of the Geological Survey, and are characterized by 

 the existence of continuous floors of grey flint, each about 6 inches 

 thick, these flint layers often containing inclusions of hard yellowish 

 chalk. Fossils are not common in these beds ; Mr. Jukes-Browne 

 informs me that Mr. A. Burnet, of Leeds, has recently found some 

 in the quarry about three-quarters of a mile west-south-west of 

 Fotherby, though unfortunately they are not sufficient to prove the 

 exact age of the Chalk containing them. Mr. Jukes-Browne has 

 identified them as follows : Septifer lineatus (in flint), Inoceramus 

 Brongniarti'? Plicatula sigillina, Bhynchonella Cuvieri, Serpula sp., 

 and a spine of Cyphosoma. The occurrence of Septifer lineatus is 



