406 Dr. Du Riche Preller—Contact-Zone of 
Between the granitic, gneissic, and amphibolic rocks as the principal 
constituents of the massif, there are countless passages; all the 
rocks with rare exceptions exhibit more or less marked evidence of 
alteration, crushing, and lamination, and intense, often vertical folding, 
in striking unconformity with the subjacent Permo-Carboniferous and 
the overlying younger sedimentary formations. 
The sedimentary formations comprise, in ascending order, the 
Permo - Carboniferous gneisses, mica-schists, and the dark, dull 
sericitic, often green chloritic schists known as phyllades or schisti 
plumbei; the paler Permo-Triassic sericitic schists, quartzites, and 
clastic Verrucano, including also the lustrous and varicoloured grey, 
green, and violet schisti rasatv}; and the Triassic dolomitic and 
fossiliferous, tegular micaceous, and black limestones, the latter 
corresponding to the grezzoni of the Apuan Alps and belonging to 
the Middle Trias. These are overlain by the Upper Trias cale-schists 
with pietre verdi. The extensive deposits of Oligocene fossiliferous 
conglomerates and breccia on the crest-line and on the flanks of the 
hills below that line are an important factor as evidence of a marine 
formation on the former, subsequently raised littoral. 
V. Tae Prosiem or Acer, Srructurz, AND ORIGIN. 
This problem has been fruitful of various, often directly opposed 
interpretations ever since 1841. Sismonda and Pareto regarded the 
erystalline rocks as primitive and protogine; Gastaldi classed them, 
including the apenninites, so called by him, as Upper Archean, 
though more recent than his calc-mica schist and pietre verdi zone. 
Zaccagna,*and with him Issel and Mazzuoli,*? in 1887 included the 
whole crystalline Savona series in the Permo-Carboniferous and 
Permian horizon of the adjoining Maritime Alps, while De Stefani,‘ 
in the same year, maintained Gastaldi’s view of the Pre-Paleozoic 
uniformity of all the crystalline rocks of the Western Alps and 
Liguria. 
Since then the most important investigations of the Savona region 
have been those of Franchi (1893), Rovereto (1895 and 1909), 
and Termier and Boussac (1911-13), followed by the dissentient 
views of De Stefani (1913), who confirms his previous ones already 
mentioned, and considers the Savona massif formed in situ. 
i Franchi, in a valuable memoir,® vindicating Pareto’s protoginic 
view, recognized the gneissic, amphibolie, and. granitic masses as 
constituting a crystalline massif older than the Permo-Carboniferous 
1 Rovereto assigns these varicoloured schisti rasati to the Middle Trias, but 
they are, as Termier and Boussac also point out, really Upper Permian. 
aD Zpecngna, ** Costituzioni Alpi Marittime’’: Boll. R. Com. geol., 1884, 
p. 167 et seq. ; “‘ Geologia Alpi Occid.’’: ibid., 1887, p. 346 et seq. 
SAY. ssel, ity Mazzuoli, & D. Zaccagna, Carta geol. Riviere Ligure, 1887 
and 1890. 
4 ©. De Stefani, ‘‘L’Apennino fra Colle d’Altare e la Polcevera’’: Boll. 
R. Com. geol., 1887, fase. 3; ‘* Zona Serpentinosa della Liguria Occid.’’: Atti 
R. Accad. Lincei, Roma, 1913, pp. 547, 661. 
> §. Franchi, ‘‘ Nota preliminare ‘formazione gneissica e sulle roccie 
granitiche del Massiccio Ligure’’: Boll. R. Com. geol., 1893, p. 43 et seq. In 
this memoir Franchi also describes the principal rocks microscopically and 
gives a list of the literature 1841 to 1893. 
