Theory of the Earth, Volume 2 (of 4) eBook

This eBook from the Gutenberg Project consists of approximately 375 pages of information about Theory of the Earth, Volume 2 (of 4).

Theory of the Earth, Volume 2 (of 4) eBook

This eBook from the Gutenberg Project consists of approximately 375 pages of information about Theory of the Earth, Volume 2 (of 4).

CHAP.  XIII.

The same Subject continued.

The Chevalier de Dolomieu, in his most indefatigable search after natural history and volcanic productions, has given us the description of some observations which are much calculated to put this subject in a conspicuous point of view.  I give them here as examples of the operation of water wasting the land and forming valleys in a system where every thing is tending to the wisest end or purpose; but they are no less interesting as proper to give us a view of the mineral operations of the globe.  That therefore which, according to the order of the subject, ought to be cited in another part of this work, is here necessarily mixed in the narrative of this natural historian.

There is, upon this occasion, such a connection of the facts by which the mineral operations of the earth, either consolidating the materials deposited at the bottom of the sea, or elevating land by the power of subterraneous heat, are to be understood, and of those by which the operations of the surface are to be explained, that while they cannot be separated in this narration, they throw mutual light upon each other.  It is in his Memoire sur les Volcans eteints du Val di Noto en Sicile.  Journal de Physique, Septembre 1784.

“Je trouvai les premiers indices de ces volcans, en allant de Syracuse a Sortino, a une lieue de cette ville, au fond du profond vallon qui y conduit.  Quelques morceaux de laves entraines et arrondis par les eaux m’annoncerent d’avance que j’allois entrer dans un pay volcanique.  Mon attention se fixa bientot apres sur un courant de laves que je vis sortir d’une montagne calcaire qui etoit sur ma droite, il etois coupe par une vallon dont les eaux couloient sur un sol calcaire, et alloit se perdre dans le massif egalement calcaire qui etoit sur ma gauche.  Je passai en suite alternativement sur des matieres calcaires et volcaniques, pour arriver a Sortino, ville baronale batie sur une montagne calcaire qui domine la vallon, et qui lui presente des escarpemens de plus de 200 toises d’elevation, dans lesquels les banc de pierres dure sont horizontaux, et exactement paralleles.”

Here, it is to be observed, are horizontal beds remaining, which give a measure of what had been abstracted by some cause, which is our present subject of investigation.  The Chevalier proceeds: 

“Les environs de Sortino m’offrirent des phenomenes et des singularites dont l’explication me parut difficile, et qui tinrent pendant longtemps mon esprit en suspens.  Je vis d’abord les matieres volcaniques ensevelies sous des bancs horizontaux de pierres calcaires, tres-coquillieres, contenant sur-tout une infinite de madreporites, quelques-uns d’un volume enorme.  Je vis ensuite des hauteurs dont les sommets seuls etoient volcaniques, et les noyaux calcaires, sans que les laves qui couronnoient ces sommets eussent communication avec aucun courant,

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Theory of the Earth, Volume 2 (of 4) from Project Gutenberg. Public domain.