8 



NOTES ON THE CRETACEOUS FOSSILS IN THE 

 EAST YORKSHIRE DRIFT. 



J. p. J.RAVN, 



Geological Museum, Copenhagen. 



For some years geologists in East Yorkshire have been famihar 

 with fossils, in pink and black flint, which occur in large numbers 

 in the glacial gravels and clays of East Yorkshire, and, to a 

 smaller extent, in North Lincolnshire. These are usually flint 

 casts of echinoderms of various species, but in addition are 

 inocerami, sponges, and belemnites. There are likewise in the 

 drift large numbers of a belemnite, of the mucronata or lanceolata 

 type, with a very deep alveolus. Whilst a few of these occasion- 

 ally occur embedded in black flint, they usually are found 

 separated from the flint or chalk, and are generally in very 

 good condition. Not only are these fossils totally different 

 from anything that occurs in the chalk of the north of England, 

 but the black and pink flint, which is so common in the drift, 

 and in which the specimens are often embedded, does not 

 occur in the Yorkshire or Lincolnshire chalk at all. 



In the museum at Hull, which is apparently the home for 

 East Yorkshire geological specimens, there is a fine collection 

 of these derived fossils, and the curator, Mr. Sheppard, has 

 enabled me to examine a representative collection therefrom. 

 In these the flint has a very great resemblance to that occurring 

 in the Danish ' Skrivekridt,' i.e., chalk with Scaphites con- 

 strictus, which is the same age as the Trimmingham Chalk of 

 East Anglia. 



As regards most of the specimens, this resemblance is so very 

 close, that it is possible to believe they were really derived from 

 Denmark. On the other hand, the fossils, with the exception 

 of a few examples, belong to species which neither occur in our 

 Skrivekridt nor as erratics in our Quarternary deposits. They 

 would therefore appear to be derived from strata older than the 

 Danish Skrivekridt. 



Of the species submitted, only the Belemnitella mucronata 

 and the Echinocorys ovatus are found in Denmark, where they 

 are very common in the Skrivekridt ; in other countries they 

 also occur in older beds. The specimens found as boulders 

 in the Danish drift are precisely similar in character and in a 

 similar state of preservation to the East Yorkshire specimens. 



Taking all into consideration, it seems more than probable 

 that the flint casts, etc., in the East Yorkshire drifts are derived 

 from deposits situated in the northern part of the North Sea, 

 as if the beds in which the fossils occur were in the vicinity 

 of the Skager Rack we should find the fossils as boulders in 

 Jutland ; but this is not so. 



Of foreign boulders from Cretaceous deposits only Neocomian 

 and Gault are found in the northern part of Jutland, and their 

 homestead is considered to be the bottom of Skager Rack. 



Naturalist, 



