Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/117

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of Devonshire and Cornwall.
105

Plymouth, by Dartmouth, Torbay, and Teignmouth. I am inclined to believe that it is the same limestone which I saw at Chudleigh and Ashburton, and which extends thus far into the interior of the country. The observations of Dr. Maton seem to support this conjecture,[1] as do those subsequently made by Lord Webb Seymour and Mr. Playfair.[2]

Nor do I know what rocks are found in situ, on the road from Exeter to Oakhampton. I can only say, that at a few miles to the east of that town, the extensive grauwacke formation commences.

Before proceeding further westward, where more constant and uniform formations will be found to exist, it may not be amiss to make here some general remarks, pointed out by the subject itself, on the nature and succession of the different formations which have been already noticed, and on what they seem to offer in the way of analogy with other countries.

It has been seen, that leaving on the borders of Dorsetshire the chalk and flint formation, and afterwards the shell limestone, a red sandstone succeeded, in strata slightly inclined, which as well as those of the conglomerate into which it passes, rest in some places on amygdaloid, in others on grauwacke, and finally on transition limestone. It is an object of inquiry which demanded more leisure than I was able to bestow upon it, to determine whether it is on one of these rocks in particular, that the argillaceous sandstone rests: but it is, I presume, a matter of secondary importance. There is another general fact of some consequence to observe, which is, the elevation of the strata the further they proceed to the westward, and the great angle of inclination they make with the horizon. Let us

  1. Observations on the Western Counties, vol. i. p. 122.
  2. Illustrations of the Huttonian Theory, p. 55, 189.