MARBLE OF CARRARA. 
599 
the Valorsine, near Mont Blanc, granite and granitic veins 
are observable, piercing through talcose gneiss, which passes 
insensibly upward into secondary strata. 
It is certainly in the Alps of Switzerland and Savoy, more 
than in any other district in Europe, that the geologist is 
prepared to meet with the signs of an intense development 
of plutonic action; for here strata thousands of feet thick 
have been bent, folded, and overturned, and marine seconda¬ 
ry formations of a comparatively modern date, such’as the 
Oolitic and Cretaceous, have been upheaved to the height of 
12,000, and some Eocene strata to elevations of 10,000 feet 
above the level of the sea; and even deposits of the Miocene 
era have been raised 4000 or 5000 feet, so as to rival in 
height the loftiest mountains in Great Britain. In one of the 
sections described by M. Studer in the highest of the Bernese 
Alps, namely in the Roththal, a valley bordering the line of 
perpetual snow on the northern side of the Jungfrau, there 
occurs a mass of gneiss 1000 feet thick, and 15,000 feet long, 
which I examined, not only resting upon, but also again cov¬ 
ered by strata containing oolitic fossils. These anomalous 
appearances may partly be explained by supposing great 
solid wedges of intrusive gneiss to have been forced in lat¬ 
erally between strata to which I found them to be in many 
sections unconformable. The superposition, also, of the 
gneiss to the oolite may, in some cases, be due to a reversal 
of the original position of the beds in a region where the 
convulsions have been on so stupendous a scale. 
Northern Apennines.—Carrara. —The celebrated marble of 
Carrara, used in sculpture, was once regarded as a type of 
primitive limestone. It abounds in the mountains of Massa 
Carrara, or the “Apuan Alps,” as they have been called, the 
highest peaks of which are nearly 6000 feet high. Its great 
antiquity was inferred from its mineral texture, from the ab¬ 
sence of fossils, and its passage downward into talc-schist 
and garnetiferous mica-schist; these rocks again graduating 
downward into gneiss, which is penetrated, at Forno, by 
granite veins. But the researches of MM. Savi, Boue, Pareto, 
Guidoni, De la Beche, Hoffmann, and Pilla demonstrated that 
this marble, once supposed to be formed before the existence 
of organic beings, is, in fact, an altered limestone of the 
Oolitic period, and the underlying crystalline schists are sec¬ 
ondary sandstones and shales, modified by plutonic action. 
In order to establish these conclusions it was first pointed 
out that the calcareous rocks bordering the Gulf of Spezia, 
and abounding in Oolitic fossils, assume a texture like that 
of Carrara marble, in proportion as they are more and more 
