[footnote] *On the transformation of compact into granular limestone by the action of granite, in the Pyrenees at the 'Montagnes de Rancie', see Dufrenoy, in the 'Memoires Geologiques', t. ii., p. 440; and on similar changes in the 'Montagnes de l'Oisans', see Elie de Beaumont, in the 'Mem. Geolog.', t. ii., p. 379-415; on a similar effect produced by the action of dioritic and pyroxenic porphyry (the 'ophite' described by Elie de Beaumont, in the 'Geologie de la France', t. i., p. 72), between Tolosa and St. Sebastian, see Dufrenoy, in the 'Mem. Geolog.', t. ii., p. 130; and by syenite in the Isle of Skye, where the fossils in the altered limestone may still be distinguished, see Von Dechen, in his 'Geognosie', p. 573. In the transformation of chalk by contact with basalt, the transposition of the most minute particles in the processes of crystallization and granulation is the more remarkable, because the excellent microscopic investigations of Ehrenberg have shown that the particles of chalk previously existed in the form of closed rings. See Poggend., 'Annalen der Physic', bd. xxxix., s. 105; and on the rings of aragonite deposited from solution, see Gustav Rose in vol. xlii., p. 354, of the same journal.
I would here wish to make special mention of Parian and Carrara marbles, which have acquired such celebrity from the noble works of art into which they have been converted, and which have too long been considered in our geognostic collections as the main types of primitive limestone. The action of granite has been manifested sometimes by immediate contact, as in the Pyrenees,* and sometimes, as in the main land of Greece, and in the insular groups in the gean Sea, through the intermediate layers of gneiss or mica slate.
[footnote] *Beds of granular limestone in the granite at Port d'Oo and in the Mont de Labourd. See Charpentier, 'Constitution Geologique des Pyrenes', p. 144, 146.
Both cases presuppose a simultaneous but heterogeneous process of transformation. p 263 In Attica, in the island of Euboea, and in the Peloponnesus, it has been remarked, "that the limestone, when superposed on mica slate, is beautiful and crystalline in proportion to the purity of the latter substance and to the smallness of its argillaceous contents; and, as is well known, this rock, together with beds of gneiss, appears at many points, at a considerable depth below the surface, in the islands of Paros and Antiparos."*
[footnote] *Leop. von Buch, 'Descr. des Canaries', p. 394; Fiedler, 'Reise durch das Konigreich Griechenland', th. ii., s., 181, 190, und 516.
We may here infer the existence of an imperfectly metamorphosed flotz formation, if faith can be yielded to the testimony of Origen, according to whom, the ancient Eleatic, Xenophanes of Colophon* (who supposed the whole earth's crust to have been once covered by the sea), declared that marine fossils had been found in the quarries of Syracuse, and the impression of a fish (a sardine) in the deepest rocks of Paros.
[footnote] *I have previously alluded to the remarkable passage in Origen's 'Philosophumena', cap. 14 ('Opera', ed. Delarue, t. i., p. 893). From the whole context, it seems very improbable that Xenophanes meant an impression of a laurel ([Greek words]) instead of an impression of a fish ([Greek words]). Delarue is wrong in blaming the correction of Jacob Gronovius in changing the laurel into a sardel. The petrifaction of a fish is also much more probable than the natural picture of Silenus, which, according to Pliny (lib. xxxvi., 5), the quarry-men are stated to have met with in Parian marble from Mount Marpessos. 'Servius ad Virg., AEn.', vi., 471.
The Carrara or Luna marble quarries, which constituted the principal source from which statuary marble was derived even prior to the time of Augustus, and which will probably continue to do so until the quarries of Paros shall be reopened, are beds of calcareous sandstone — macigno — altered by Plutonic action, and occurring in the insulated mountain of Apuana, between gneiss-like mica and talcose schist.*
[footnote] *On the geognostic relations of Carrara ('The City of the Moon',
Strabo, lib. v., p. 222), see Savi 'Osservazioni sui terreni antichi
Toscani', in the 'Nuova Giornale de' Letterati di Pisa', and Hoffmann, in
Karsten's 'Archiv fur Mineralogie', bd. vi., s. 258-263, as well as in his
'Geogn. Reise durch Italien', s. 244-265.
Whether at some points granular limestone may not have been formed in the interior of the earth, and been raised by gneiss and syenite to the surface, where it forms vein-like fissures,* is a question on which I can not hazard an opinion, owing to my own want of personal knowledge of the subject.