Note 11 — Chapter V · GALAPAGOS ARCHIPELAGO.

This conclusion is of some interest, because M. Dufrenoy (“Mém. pour servir,” tome iv, p. 274) has argued from strata of tuff, apparently of similar composition with that here described, being inclined at angles between 18° and 20°, that Monte Nuevo and some other craters of Southern Italy have been formed by upheaval. From the facts given above, of the vaulted character of the separate rills, and from the tuff not extending in horizontal sheets round these crateriform hills, no one will suppose that the strata have here been produced by elevation; and yet we see that their inclination is above 20°, and often as much as 30°. The consolidated strata also, of the internal talus, as will be immediately seen, dips at an angle of above 30°.