360 ME. W. HILL Olf THE LOWEK EELS OE THE "UPPER 



At the exposure near Wharram Grange, about 3^ miles N.E. of 

 Leavening, the colour of the Eed Chalk is lost, and fossils {Inocera- 

 mus sulcatus, Belemnites minimus) which occur in the Gault or 

 Hunstanton Limestone are found in a dirty yellow-coloured material, 

 the gritty character of which is similar to that of the Inoceramus-'bQdL 

 at the base of the Chalk Marl. 



It is unfortunate that from the broken-up condition of the Chalk 

 at this exposure the evidence to be obtained as to the sequence of 

 the beds is not very reliable, yet the gradual attenuation which 

 has just been noted from south to north, and the change in the 

 character of the rock at this point, might lead one to infer that the 

 Eed Chalk did not extend originally much further to the north-west 

 in Yorkshire, but was overlapped by the beds representing the Chalk 

 Marl ; but the evidence on this point is insufficient. Its characters, 

 however, are persistent to the eastward if it does not actually thicken, 

 for Prof. Blake * records 2 feet of Eed Chalk near Wharram Station, 

 about a mile to the east of the exposure near ^' harram Grange, and 

 Mr. Mortimer f records its thickness as "2 feet in Pairy Dale, just 

 north of Burdale tunnel, and 2^ miles east of the Grange exposure. 



Chemical analysis and microscopical examination show that the 

 deposit from South Lincolnshire to its most westerly point in York- 

 shire is almost a purely calcareous one, made up chiefly of Porami- 

 nifera and amorphous calcareous material. 



In the early part of Upper Cretaceous time, land doubtless existed 

 over the central parts of northern England and formed the western 

 shore of the Cretaceous sea. It is remarkable, considering the 

 contiguity of this coast-line, that the effects of its waste should not 

 have been more evident in the Chalk of the area we are now discussing. 

 The calcareous nature of the deposit, however, shows that it was 

 probably laid down in quiet water of considerable depth, out of the 

 reach, or away from the path, of detritus-carrying currents. 



Mr. Jukes-Browne has suggested to me that the Pennine Chain 

 may have extended southward as a promontory from the continental 

 land which probably limited the Cretaceous basin in the north and 

 north-west, and that its area was not sufficient to give rise to any 

 large rivers ; possibly, too, its drainage was mainly directed to the area 

 of the Irish Sea. These conditions would probably much resemble 

 those which now exist in the Gulf of Genoa, the Maritime Alps 

 taking the place of the Pennine Chain. 



Although the Eed Chalk in the area now under discussion is 

 unlike its more southern equivalent, the Gault, the occurrence in 

 Lincolnshire and Yorkshire of such forms as Ammonites interruptus^ 

 Ammonites rostratus, and Inoceramus sulcatus in this bed is a further 

 proof of the stratigraphical relations of the one to the other. 



In the roughly defined curve caused by the gradual alteration in 

 the direction of the outcrop of the chalk from IST.W. to E.IS'.E., 

 Leavening is at the most westerly and Wharram at the most north- 

 westerly point of the outcrop. 



* Proc. Geol. Assoc, vol. v. p. 245. 



t Proc. Yorksh. Geol. and Polyt. Soc. vol. ix. p. 32. 



