the Alps and Apennines in Liguria. 401 
and the other or Savona group, which skirts the littoral for about 
15 kilometres from Celle to Savona and Zinola, and is composed for 
the greater part of a crystalline massif of granitic, gneissic, and 
amphibolic rocks. 
Both these self-contained groups present respectively geological 
features entirely different from those of the adjacent areas east and 
west. Having examined them both some years ago, I propose to 
confine the present paper to the crystalline massif of Savona, which, 
owing to its altogether abnormal position and composition, is of 
absorbing interest, and has within recent years been the subject of 
remarkable interpretations as an overthrust zone par excellence. The 
Voltri group I propose to consider in a future paper in connexion 
with the adjoining ophiolithic area of Eastern Liguria. 
II. Generat Fraturss. (Fig. 1.) 
The Savona Hills form approximately a rectangular area about 
15 and 10 kilometres in length and width or 150 square kilometres, 
its general direction being south-west to north-east. On the south 
a rugged, craggy wall of gneiss runs along the coastline with some 
intervening Pliocene deposits at Celle, Albissola, Savona, Fornacci, 
and Zinola. On the west it skirts, from the coast upwards, the 
Permo-Carboniferous formation to Quiliano, Roviasca, Monte Curlo, 
and the village of Altare, a commanding point on the divide between 
Liguria and Piémont, at about 600 metres altitude. Thence, on the 
north, it follows the crest-line of the Apennines to Mte. Castlas 
(851m.), Mte. San Giorgio (840m.), and Mte. Greppino (811 m.) 
to the village of Corona in Triassic and Tertiary strata. On the east, 
from Corona down to the coast at Celle, the border coincides with the 
junction line of the cale-schists and pietre verdi of the Voltri group, 
along which lie the villages of Piazza, Vetriera, Gameragna, Sanda, 
and Ferrari. 
Within this rectangular area the hills rise near the coast to 300 
‘and 400 metres altitude, including Madonna degli Angeli immediately 
north of Savona, and Madonna del Monte in the south-west corner 
near Zinola; then in the centre to 500 and 600 metres altitude, 
notably Mte. Curlo, Mte. Ciuto, Mte. Cucco, and Mte. Castellazzo; and 
lastly to the crest-line up to 850 metres altitude, including, besides 
the points already mentioned, Mte. Pra (817 m.) and Mte. Negino 
(703 m.). ‘The hills are intersected by numerous torrents, generally 
in deeply eroded ravines, running towards the coast, the principal 
ones being the Quiliano and Quazzola at the western end, the 
Letimbro with its affluents the Canova, Gea, and Lavanestra in 
the centre, and the Sansobbia with its tributaries the Riobasco, 
Piantavigna, and Montegrosso at the eastern end. 
All the localities, points, and ravines mentioned are geologically 
important for the examination of this extremely complex area, access 
to which is rendered easy not only by the Savona and Turin railway 
traversing its central and western part in numerous tunnels and 
cuttings, but more especially by the roads which run from different 
points of the Riviera road up into the hills. Among these are the 
great highway from Savona to Cadibona and Altare into Piémont, 
DECADE VI.—VOL. III.—NO. IX. 26 
