haie 
GEOLOGICAL HISTORY OF SERPENTINES, OT 
and calcareous rocks, opposing less resistance, have been removed by decay and erosion, 
adducing many instances in support of this among the Alps. This being the case, he adds, 
we are not to be surprised when in the Apennines we find an isolated masses of ophiolite 
rising out of the midst of surrounding jurassic, cretaceous or tertiary strata, which conceal 
the rocks that accompany the ophiolite. Thus it is, he adds, that “the notion has arisen 
in the Apennines that the serpentines, diorites, etc., are always eruptive rocks.” They are, 
in his view, to make use of the happy expression of Roland Irving in describing a similar 
occurrence, “protruding but not extruded.” These views were reiterated by Gastaldi in 
his letter to Zezi in 1876, when he asserted that the skeleton of the Apennines is a conti- 
nuation of that of the Alps, and that the crystalline rocks of the Apennines are Alpine 
rocks. From the summit of Mont Blanc, he declared, they may be followed, more or less 
concealed by overlying strata of more recent date, * to the Danube, to the plains of France, 
to the Mediterranean, and along the peninsula which separates this sea from the Adriatic ; 
assertions which he supported in 1878 by many detailed observations to be noticed far- 
ther on. 
§ 87. These bold generalizations of Gastaldi have met with but partial acceptance in 
Italy, as may be seen by the discussions in 1881, and the publications of the R. Comitato 
Geologico and the Società Geologica Italiana in 1881 and 1882, already referred to in § 43. 
Pellati, in his summary, declares that the views of Gastaldi as to the anti- 
quity of the Alpine pietre verdi.are confirmed by the work of Baretti and of Taramelli, the 
latter of whom clearly shows that the view entertained by so many that these rocks are 
carboniferous or triassic, is inadmissible. Hence these ancient serpentines are by Pellati 
designated as pre-paleozoic (eozoic.) This view he extends to all the ophiolitic masses 
situated in the Alps, to those of Calabria. and also to those of the Apennines west of the 
meridian of Genoa, those to the cast of this meridian being included in the eocene. § 47. 
§ 88. Regarding the so-called eocene serpentine, and its associated rocks, Pellati 
observes, “as to its composition, it differs but little from the older serpentine, the differences 
remarked being principally in a structure ordinarily less schistose, and in a greater fre- 
quency of subordinate ophiolitic rocks ; euphotides, eurites, diorites, variolites, ophiocal- 
cites, etc., more or less decomposed. The masses of proper serpentine are ordinarily more 
scattered and of smaller dimensions, having almost always gabbros and beds of phthanite 
and jasper around them.” Cossa, it is true, has remarked in the specimens examined by 
him that the mineral species bastite is more common in the eocene or Apennine than in 
the eozoic or Alpine serpentines, but, with this possible exception, the mineralogical and 
lithological associations of the two are apparently identical. In fact, Pellati admits that it 
is in some cases difficult, if not impossible, to distinguish between them. Within the great 
basin lying to the east of the meridian of Genoa, and embracing, as we have seen, the so- 
called tertiary serpentines, we are informed by him that “the paleozoic and mesozoic rocks 
are generally very thin, and often are entirely absent, in which case the floor of pietre verdi 
or greenstones is directly overlaid by the tertiary, and in fact by the very eocene which 
includes the younger serpentines. This is the case in the vicinity of Genoa, upon the right 
bank of the Polcevera, where the greenstones come in direct contact with the shales and 
the limestones of the upper eocene, and it here becomes doubtful whether, along this line 

* See the author on Azoie Rocks, p. 245. 
