156 Harker: Lake District Rocks, 
formerly more. It is a matter of history that this spit of 
shingle, now more than three miles long, is the growth of the 
last three centuries. In 1586, the date of Camden’s ‘Magna 
Britannia,’ it did not exist. What, then, has become of the 
millions of tons of material swept southward along the Holder- 
ness coast prior to that time? There is only one possible 
answer: it is distributed along the coast south of the 
Humber. 
The cycle of events which must have recurred many times 
since the Glacial Period, when this district was formed, is easily 
h 
begins to form at Spurn, as it did in Camden’s time, the point 
lengthens more and more, the neck becomes thin, the sea 
reaks through, and a bank of shingle becomes detached. Then 
the north channel becomes wider and wider, as the sea and 
wind drive the island southward, like any other part of the 
beach, till at last the bank is transferred from Yorkshire to 
Lincolnshire, and the process recommences.’ 
Clement Reid points to the existence of a very large shingle 
beach near Donna Nook, on the south side of the Humber. 
mouth, which can only have been derived from the other side of 
the estuary; but there are many vanished Spurn Points to 
account for, and it cannot be doubted that the material from 
them is scattered along the coast from the Humber to the Wash 
at least. Hence, while not denying the possibility that some of 
the boulders on the Lincolnshire coast may have a different 
source, I adhere to the view that many, and probably the large 
majority, of them are derived from the waste of the Holderness -_ 
cliffs 
oe 
NOTE—GEOLOGY. 
Lake District Rocks: Additional Note. The sarin hicair 
eae of rocks in the Ordovician Volcanic Series are addit nal to — 
the Chemistry of Lake District Rocke (Nat, Bs 
ate on 
Feb. 1899, pp- 53-58, and May 1899, pp. 149-154). 
6. Gatherstone Head, Black Sail Pass: porphyritic basalt, felspars 
partly epidotize 
2°744. Eycott mp a? apparently No. 16 of Ward's section. 
4 Gill: 
2°735- Brund Gill, Hetvelly n, N.E. of sheep-fold: 1 
3 
2°715. Pdesacty Gill e 600 feet contour-line: cneaaeitacens lava. 
2°672. Rosgill Moor, pions Swindale, — engage 
2°671. E. of Grang e Bri dge, Borrowda le: an 
— Summit of  Ridsty Pike: nodule in rh ae 
‘565. About  m. N.E. of Applethwaite Common : rhyolite. 
Pe FRED Seay Cambridge, 1st April Se 
Naturalist, 
~ 
sl ee pias ts 
: 
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