490 Dr. Du Riche Preller—Ophiolithic Rocks, HE. Liguria. 
euphodite alternating with argillaceous schist all more or less 
decomposed, except the euphodite with felspathic base and smarag- 
dite of Bonassola, which, though it exhibits secondary minerals, is 
comparatively fresh.’ The principal outcrops inland are exposed 
along the road from Levanto to La Baracca (600 m.), where the 
ophiolithic series may be conveniently studied in the numerous 
quarries of the beautiful and well-known ‘‘ green marble of Levanto ” 
largely used for ornamental purposes. It is essentially compact 
serpentine, greenish and rusty red, with clear white veins which are 
fissures filled with calcite. ‘The rock passes to a more crushed and 
brecciated variety, re-cemented by calcium carbonate as ophicalce. 
Another variety is the so-called ranochiaia or frog-coloured, which in 
a greenish yellow groundmass exhibits fine, black, arborescent tissues 
of opacite. The compact serpentine also passes to schistose, fibrous, 
and steatitic, is often spheroidal, and, when it contains enstatite, 
diopside, bronzite, and notably diallage, is porphyric in structure. 
Along the same road serpentine often alternates with euphodite more 
or less altered, and with intermediate strips of pseudo-serpentine. 
The ophiolithic rocks are normally intercalated between argillaceous 
schists as the lower, and limestones as the upper strata, with 
occasional intervening claret-coloured diaspri. North of the Sestri 
and Spezia road occurs the cluster of serpentine and euphodite masses 
of Tavarone between Castiglione and Maissana, of Velva, Carro, 
Baracchino, and Matterana (Bracco), in all of which the euphodite is 
largely gneissiform and, notably north of La Baracea, forms a con- 
siderable area. Another interesting mass is that near Pignone, about 
10km. east of Levanto and the same distance north of Spezia, 
which constitutes, in the Eocene strata, a band of about 8 by 1 km. 
of serpentine and euphodite, like those of the Levanto group.” It 
runs north-west to south-east, parallel to the latter and to the coast 
towards the Cretaceous, Liassic, and Rhetian strata of the Porto 
Venere or western arm of Spezia Bay, and forms the link between 
the ophiolithic groups of Eastern Liguria and those 15 km. further 
east of Sarzana, Lunigiana, and Garfagnana in the Magra and upper 
Serchio Valleys along the northern margin of the Apuan Alps. 
II. Tue Monte Branco Grove. (Figs. 1-4 and 6.) 
This ophiolithic and remarkably metalliferous area is situated 
north-west of the Levanto group; its lower end, touching the Sestri 
and Spezia road near Bracco (448 m.), lies about 6 kilometres north of 
the former town. It covers about 10 by 5 kilometres, and is crossed 
north-east to south-west by the deeply eroded ravines of the Graveglia, 
Gromolo, and Petronia torrents in its northern, middle, and southern 
part respectively. It is traversed north to south by three more or 
less parallel ridges, viz. anticlinal folds dipping west, the highest 
1 Some of the rocks near Levanto. were described by Professor Bonney in 
op, cit., GEOL. MAG., 1879, p. 362 et seq. 
2 Specimens of the Pignone group were examined microscopically by 
Professor A. Cossa of Turin, who also gives analyses of the same in comparison 
with some of the similar Ligurian and Tuscan rocks (Boll. R. Com. geol., 1881, 
p. 246 et seq.). 
