270° Address to the Lincolushtve Naturalists’ Union. 
“Challenger” calculations, at the rate of a foot in a century at 
the most, the chalk, which is now some 1,300 feet thick,—and 
had, at one time, another 1,000 feet at the top of it, which has 
since been swept away,—the time occupied in the formation of 
these chalk beds must have been enormous. At the above rate of 
a foot of sediment in a century, the lost 1,000 feet alone would 
have taken 100,000 years to form, 
Now, that the neighbourhood of such an ocean as this, which 
reached from Ireland, over Europe, to the Crimea, should have 
greatly affected the area we are considering, is not tu be wondered 
at. 
For a long period, during the existence of the Oolite and 
higher Jurassic seas,—when the land to the east of Lincoln, 
between it and the chalk wolds, was being formed,—the Triassic, 
Rhoetic and Lias beds on the west had become dry land; but, ~ 
as the chalk sea grew, the weight of its deposits caused the land 
all round to sink, and, as this sea, at last, covered nearly the 
whole of England and Wales, the district between Gainsborough 
and Lincoln, with all the western land, was buried far beneath its 
waves. 
Now the action of a sea is always that of a leveller, and as 
in course of ages, the cretaceous ocean itself passed away, the 
land beneath it, as it rose again to the surface, presented a smooth 
plane of erosion, gradually sloping up to the higher lands around, 
which had, during this epoch, remained dry ground. 
At this time,—a period when the Pyrenees were thrown up,— 
England, Scotland, and Ireland were, probably, as Mr. Jukes 
Browne tells us, bound together in one mass. Land lay far out 
into the Atlantic on the west, and land connected Scotland with 
Greenland, through the Faroes and Iceland, on the north, and 
with Scandinavia on the east. 
How far, and to what extent, the area between Gainsborough 
and Lincoln was denuded, during this great erosion, we shall never 
know; but, as it rose higher and higher above the waves, the 
carving tools of nature were brought into play, and rain, frost, 
and other forces of the atmosphere began their ceaseless work. 
