380 CRETACEOUS, 



a strong contrast to them in lithological character, and in being, 

 except for the derived fauna, entirely unfossiliferous. It is 

 composed of such materials as would result from the "washing" of 

 the Tealby beds. In general it is a reddish-brown grit, made up 

 of small quartz-pebbles, flakes and spherical grains of iron-oxide, 

 with rolled phosphatic nodules. Towards the. south, where it is 

 thick, the nodules are small and sporadic ; but northwards, as the 

 Carstone becomes thinner, they increase in size and abundance, 

 so as to form a " coprolite-bed," and have yielded specimens of 

 Ammottites Speetonensis, A. plico/Jiphahis, Lucina, etc. When the 

 Carstone finally thins out, the conglomeratic character invades the 

 Red Chalk, similar nodules being then found in this rock. The 

 presence of these nodules, with their organic remains, taken in 

 connexion with the character of the materials of the Carstone, 

 points to considerable erosion of the Tealby beds. On the other 

 hand, there is a passage from the Carstone up into the Red Chalk, 

 as noticed by Mr. C. J. A. Meyer.^ Hence in Mr. Strahan's 

 opinion the Carstone should in this area be regarded as a " base- 

 ment-bed " of the Upper Cretaceous rocks.'^ 



The Carstone was described by Prof. Judd under the name of the 

 Upper Ferruginous Sands, and is from 20 to 40 feet in thickness. 

 The term Langton Sand, from Langton, near Spilsby, has been 

 used by Mr. Jukes-Browne. 



The Tealby Series, so named by Prof. Judd, from Tealby north- 

 east of Market Rasen, consists of beds of limestone (greystone), 

 and sandy clay, from 40 to 50 feet thick ;^ underlaid by beds of 

 sand and sandstone, from 30 to 40 feet thick. These beds are now 

 divided into the Tealby Limestone, the Donnington Clay, named 

 by Mr. Strahan from Donnington, south-east of Louth ; and the 

 Spilsby Sandstone, named by Mr. Strahan from the town of that 

 name. The Tealby series yields Pecieti ductus (9 to 12 inches in 

 diameter), P. orbicularis, Exogyra sinuaia, Osirea frons, Behmnites 

 semicanaJicuIatus, Rhyncho7iella parvirosiris, etc. The fossils obtained 

 from the Spilsby Sandstone at Bolingbroke, etc., include many 

 Oolitic forms. ^ 



Iron-ore composed of oolitic grains of hydrated peroxide of iron has been 

 worked in the Tealby Beds, at Claxby and Nettleton, and pisolitic iron-ore was 

 formerly worked at Walesby.^ The coarse sandstone of the series has been used 

 for building-purposes. 



Speeton Clay. — The Speeton Clay, so named by Prof. Phillips in 

 1829, consists of a series of black and dark-blue clays, sometimes 

 bituminous, pyritic, or slaty, and it attains a thickness of 500 feet. 

 It was termed the Upper Shale by Young and Bird in 1822. 



The section of Speeton Clay occurs on the coast to the north 

 of Flamborough Head, where the strata are much disturbed and 

 obscured by slips ; the clay extends inland to Knapton, etc. The 



1 G. Mag. 1869, p. 13. 2 Q. J. xlii. ; p. Geol. Assoc, viii. 386. 



2 Q. J. xxiv. 236. See also W. H. Dikes and J. E. Lee, Mag. Nat. Hist. i. 560. 



* Jukes-Browne, Geol. E. Lincolnshire (Geol. Surv.), 1886. 



* Morris, G. Mag. 1867, p. 460; see also H, Keeping, Q. J. xxxviii. 239. 



