EXPLANATION OF THE PLATES.
Introductory Notice, and Description of the Geological Phenomena illustrated by Plate I.
Plate 1,
Is an imaginary Section constructed to express, by the insertion of names, and colours, the relative positions of the most important classes, both of unstratified and stratified rocks, as far as they have yet been ascertained. It is founded on many series of accurate observations, on several lines taken across Europe, between the British islands and the Mediterranean Sea. Although no single straight line exhibits every formation complete in the full order of succession here represented, no fact is inserted for which authority cannot be found. The near approximation of this synoptic representation to the facts exhibited by an actual section, may be estimated by comparing it with the admirable section across Europe, published by Mr. Conybeare in the Report of the Proceedings of the British Association for the Advancement of Science, 1832, and with his sections of England, in Phillips and Conybeare's Geology of England and Wales.
The chief merit of the above Section is due to the Talents of Mr. Thomas Webster; it is founded on a more simple section which has for several years been used by him in his lectures, and which exhibits the relations of the Granitic and Volcanic rocks to the stratified formations,
