22 DESCRIPTION OF THE STRATA. 



Holdeniess cliffs are speckled with numerous fragments of chalk ; 

 and the white colour obviously increases as we approach to Flam- 

 borough, especially as the marl becomes cretaceous in the neighbour- 

 hood of the chalk. In like manner, as the gravel near Whitby 

 abounds with pieces of sandstone, the gravel near Flamborough 

 abounds with fragments of chalk and of flint. 



It has been observed, that beds of sand and gravel sometimes 

 alternate %vith the lower beds of clay, as well as the higher, and may 

 be seen near Whitby at the foot of the alluvial cliffs, very little above 

 the solid rock. Examples of the same kind occur in the alluvium 

 that covers the chalk; particularly at Bridlington Quay, where a 

 bed of cretaceous flinty gravel, of considerable thickness, is found 

 immediately over the chalk. This bed, like many other gravel beds, 

 is a receptacle for waters, and the parent of copious springs; some 

 of which are seen issuing from the cliff to the north of Bridlington 

 Quay, just before we arrive at the chalk rocks. 



The most remarkable spring proceeding from this gravel bed, is 

 the ebbing and flowing spring of Bridlington Quay. This most co- 

 pious fountain was discovered in 1811, when, with a view to the 

 improvement of the harbour, the alluvium which forms its bed was 

 bored through. The alluvium was found to consist of a bed of com- 

 pact clay, 28 feet thick, and a bed of cretaceous flinty gravel, 15 feet 

 thick; beneath which was the solid chalk. At first there was no 

 indication of a spring, but after the aperture was made, a plentiful 

 supply of excellent fresh water rOse in it with the rise of the tide, 

 and not only filled the bore completely, but flowed over in a power- 

 ful stream, being projected some inches above the top of the bore. 

 It boiled up with most impetuosity at high water, and gradually fell 

 as the tide retired. The same phenomenon has continued ever since; 

 and the inhabitants, to secure the benefits of this valuable spring, 

 have fixed a tube in the bore, to receive the rising column of water. 



