THE 



QUARTERLY JOURNAL 



OF 



THE GEOLOGICAL SOCIETY OE LONDON, 



PROCEEDINGS 

 THE GEOLOGICAL SOCIETY. 



December 19, 1849. 



The following communication was read : — 



On Craters of Denudation^ with Observations on the Structure 

 and Growth of Volcanic Cones. By Sir Charles Lyell, Pres. 

 Geol. Soc. 



In the first edition of my ' Principles of Geology,' published in 1830 

 (vol. i. ch. 30), I explained the grounds of my objection to the 

 theory previously advanced by Baron von Buch to account for the 

 origin of the Caldera of Palma, the Gulf of Santorin, and other 

 bowl-shaped canities of large dimensions, for which he proposed the 

 name of *' Craters of Elevation." I regarded the circular escarp- 

 ments surrounding these vast cavities as the remnants of cones of 

 eruption, the central parts of which had been destroyed, and I con- 

 ceived that the removing cause had been chiefly, if not wholly, en- 

 gulf ment. 



In the second edition of my * Principles,' published in 1832, or two 

 years later, I discussed more particularly the origin of the single deep 

 gorge, which in Palma, Barren Island, and other so-called elevation- 

 craters, forms a breach in the circular range of cliffs, surrounding the 

 central cavity. This ravine or narrow passage I attributed " to the 

 action of the tide during the gradual emergence from the sea and up- 

 heaval of a volcanic island" (ch. 22. vol. i. p. 452), and I at the 



VOL. VI.— PART I. R 



