182 DR. THOMAS STERRY HUNT ON THE 
To the east of this meridian, according to Pellati, we find the newer or tertiary ser- 
pentines, including, first, those of eastern Liguria, which have their greatest develop- 
ment along a line running north-northwest from Spezzia, and second, those of the Bolo- 
enese Apennines, consisting of a great number of small masses scattered between Florence 
and Reggio in Emilia. A third group includes the masses of serpentine found between 
Grosseto and San Miniato, in addition to which tertiary serpentines are indicated in Elba, 
and in the upper part of the valley of the Tiber. Further south, others are met with at 
Lagonegro in the Basilicate, from which point to Neopoli a remarkable development of 
serpentines is found along the upper part of the valley of the Sinni. The areas of ser- 
pentines, thus indicated by Pellati, are, according to him, generally found in the midst of 
the limestones, argillites, and sandstones of the eocene, except in the case of those 
between Grosseto and San Miniato, the outcrops of which are often seen rising out of 
pliocene clays and sands. 
IV.—Rocks oF THE ALPS AND THE APENNINES. 
§ 48. Before proceeding farther in the discussion of the Italian serpentines, it will be 
well to get a view of the present state of our knowledge of Alpine geology, and especially 
of the conclusions and generalizations of Gastaldi. These, so far as the Alpine serpentines 
are concerned, are, as we have seen, accepted by the Comitato Geologico, and this conceded, 
it is difficult to escape his wider generalization which brings the whole of the so-called 
tertiary serpentines of Italy into the same eozoic horizon with those of the Alps. 
If we go backward to the early history of Alpine geology, we shall there find the 
origin of the well-known hypothesis that the crystalline stratified rocks are but portions 
of paleozoic or more recent sediments which, in certain parts of their distribution, have 
undergone a process of alteration or so-called metamorphism. The infra-position of the 
uncrystalline to the crystalline rocks in Mont Blanc, first noticed by de Saussure, was thus 
explained by Bertrand ; who suggested that these crystalline schists were altered rocks of 
a more recent date than the uncrystalline mesozoic strata of Chamonix. This notion was 
adopted without critical study by Keferstein, Murchison, Lyell, Studer, Sismondi and Elie 
de Beaumont, among others, till it was generally believed that the crystalline rocks of the 
Alps are wholly or in great part of mesozoic and cenozoic age. It is hardly necessary to 
say that this hypothesis in the Alps, as elsewhere, was based upon false stratigraphy. [have 
elsewhere discussed it in its relations to Alpine geology, in a review of the great work of 
Alphonse Favre, * whose life-long studies in the Alps of Savoy, have shown for all that 
region the fallacy of the metamorphic hypothesis. The farther studies of Gerlach, of Fr. von 
Hauer, of Baretti, and especially of Gastaldi, have now fully established the great antiquity 
of the crystalline rocks in question, and have enabled us to compare them with the pre- 
Cambrian rocks of other regions. It is not here, however, the time nor the place to discuss 
this question, except so far as is necessary to the understanding of the geological relations 
of the Italian serpentines. 
§ 49. The work of Gastaldi, interrupted by his death in 1878, was sifted bie left 
incomplete. We have, however, valuable records of it in a memoir in two parts, published 

(*) Amer. Jour Science, 1872, vol iii., pp. 9-10, and Chemical and Ceological Essays, pp. 337-339, 

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