the Alps and Apennines in Liguria. 409 
while the last three represent the most advanced types of myloniti- 
zation, the rocks being reduced to a trachytic, phonolitic, and, as 
the last stage, to a talcose aspect, completely mashed and laminated, 
no minerals being microscopically recognizable. These rocks occur 
more especially along the friction surfaces of the massif. The seven 
varieties may be studied along the roads leading from the coast into 
the hills, and notably along the paths leading from Savona up to 
Monte Negino in the central part of the area. 
4. The cataclastic structure and chaotic condition of the crystalline 
rocks are, in the author’s view, dominant features in favour of the 
massif being an overthrust em bloc. The striking unconformity, 
often at right angles, between the massif and the underlying and 
overlying formations, and its wedge-like form, thinning out from 
1,000 metres in thickness in the centre to 200 metres at its north- 
western end, viz. in the direction of thrust, afford evidence not of 
a merely local and partial displacement but of the exotic origin of the 
entire massif. 
5. The upper transport and friction surface of the massif is, in the 
author’s view, evidenced by the extremely disturbed and brecciated 
condition of the overlying younger formations in contact with the 
crystalline rocks. While the upper surface thus forced itself below 
those formations, the lower surface glided, like a traineau écraseur, 
along the gently undulating surface of the ‘ fixed’ Permo-Carboniferous 
substratum. Thus the Savona massif was, in the author’s view, 
transported subterraneously, in a fucte prodigieuse (sic) from the east, 
its rooted origin being, in common with the granite massifs of Kastern 
Corsica and Elba, in the Dinarides.! 
The two parallel sections south to north, Figs. 2 and 3, illustrate 
respectively Rovereto’s and Termier & Boussac’s overthrust inter- 
pretations; Fig. 4 represents an alternative interpretation explained 
at the end of this paper. The sketch-map, Fig. 1, gives, in dotted 
lines, the approximate zonal direction and distribution of the 
crystalline rocks; but the countless passages of the three principal 
rocks preclude any clear definition of limits. 
VI. Conctusion. 
Without in the least disparaging the overthrust theory per se, which 
in specific cases offers the only tangible explanation of stratigraphical 
anomalies, it may, in my opinion, be safely averred that as regards 
the Savona massif, all the individual and collective phenomena so 
ably marshalled by Rovereto and Termier & Boussac lend themselves 
with equal, perhaps greater force to a more natural and rational 
interpretation. . 
The Savona region, whose crest-line at Mte. Castlas, Mte. S. Giorgio, 
and Mte. Greppino lies at about 825 metres altitude, forms a depression 
between Mte. Settepani (1,391 m.) in the Maritime Alps on the west 
1 The theory of the Dinarides being the rooted origin of the three granitic 
areas is founded on G. Steinmann’s often-quoted memoir, ‘‘ Alpen und 
Apennin,’’ Monatsber. Deutsche Geol. Ges., 1907, p. 177 et seq.; his ‘‘dinaric 
coyer-sheets ’’, however, are assumed to have been transported, not direct from 
east to west, but circuitously along the curve-line of the Alps. 
