364 Rev. J. F. Blahe — On the Red Chalk in Yorkshire. 



the older rocks. Tliese conglomerates are no doubt littoral deposits, 

 and the shore would contain hollows which would be filled from 

 various sources, and these jDatches, it may be remarked, occur where 

 there is irregularity in the lower strata. 



Seeing that the Chalk is a deep-sea deposit, we have evidence of 

 the sinking of the land in these Upper Cretaceous times, so that 

 the passage-beds from the Upper Neocomian to the Aptien were 

 laid down in various areas from various sources, and thus we have 

 the great variety which characterizes these beds. But when the 

 Eed Chalk Epoch arrived, the depression was sufficient to enable that 

 rock to spread pretty uniformly over a wide area, though not to be 

 entirely without interruptions, as was the case with the White Chalk 

 which succeeded ; for there are gaps and varieties of level in the Eed 

 Chalk that may be better accounted for by an irregular surface than 

 by faults. 



Ammonites Deshayesi evidently lingered on during the time that 

 the earlier of these changes were taking place, being the last to 

 disappear at Hunstanton, lingering on in Yorkshire till the Eed Chalk 

 began, and at Folkestone, till the Gault set in. Thus the Eed Chalk 

 of Yorkshire represents the latter formation ; but as it appears to 

 have been an area of slow deposition, the few feet of it must represent 

 the whole interval during which the Gault and Greensand were 

 being deposited elsewhere, and the occurrence of the peculiar 

 Terebratula capUlata associates the basin with that of Hunstanton. 



Mr. Judd mentions that in Lincolnshire there are beds of Eed 

 Chalk intercalated between two of White Chalk, with the true Eed 

 Chalk, or Hunstanton Eed Eock, some 20 or 30 feet below. The 

 same is the case in Yorkshire. Both beds may be well seen at 

 the village of Warter, but their lithological characters are generally 

 distinct ; the upper beds are simply chalk coloured red ; whereas 

 the true Eed Chalk with much of calcareous matter unites much of 

 arenaceous, and small round grains are common of the same dark 

 rock which furnished the older conglomerate. The rock, however, 

 at Si3eeton, which contains Bel. minimus is of the former kind, so 

 that the distinction, though common, is not universal. 



While writing of bands in Chalk, I may as well notice a curious 

 phenomenon seen in a chalk-pit near Londesborough. This is the 

 existence, between beds of undisturbed chalk, of several stratified 

 layers of brown carbonaceous claj's between one and two feet thick, 

 the bottom layer quite black and thinly laminated ; all of them fol- 

 lowing the bends of the Chalk strata, the upper of which is perfectly 

 stratified, though broken in small joints ; the lower is more compact. 

 This pit must have been near enough to land to be influenced by the 

 deposit of some flood which carried off the soil of some Cretaceous 

 forest. Mr. Mortimer mentions some clay -beds at Driffield, and Mr. 

 Whitaker in the South of England in Chalk ; but they are not said 

 to be carbonaceous. 



