GENERAL OBSERVATIONS ON THE STRATA.

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appearance at low water in many places, both on the Southernand Northern shores. From the above examination, however, itis evident, that the strata on the south side of the island belongto those found under the chalk in other parts of England; hutthat the strata on the north side are extremely different, both inthe substances themselves, and in the fossils which they contain;and that some of these latter do not agree with any other knownstrata in this country. There is more difficulty, therefore, inascertaining what was the original relative situation of the strataon the north side of the island with respect to the rest, since theymerely come up against the vertical clay that adjoins the chalk,and it does not at first appear clear what was their position withrespect to it.

I trust that I shall he able to shew, that these strata on thenorth side of the island belong to those above the chalk ; andthat here are found portions of strata higher in their geognosticplace, than any others in Great Britain.

It is* almost unnecessary to mention what is now so well known,that the chalk formation throughout the south-east part ofEngland is divided into three beds,* of which the upper oneonly contains nodules of flints.

The order of the beds above the chalk, in the southern countiesof England, is not yet completely established; and, probably,from their want of continuity, and their not occurring in sufficientregularity, it is not possible to assign to them their relativesituations in all cases.

* See the Memoir in the Transactions of the Geological Society , Vol. II. {£ On thefreshwater formations in the Isle of Wight, with some Observations on the strata over thochalk in the south-east part of England,” by the author of these Letters.

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