12 _ Dr. Dw Riche Preller—Permian in 
The Permian formation reaches a thickness of at least 1,000 metres, 
and rests directly and conformably upon the fossiliferous Carboniferous 
strata, which attain about half that visible depth and constitute 
the lowest zone of the Montgioie range. The latter strata are, as 
usual in the Alps, composed in the main of blackish carbonaceous 
and grey micaceous schists, graduating into talcose greenish cale- 
schists, which become felspathic and then pass into quartzose schist, 
which forms the base of the Permian formation. The Carboniferous 
age of the strata underlying the Permian, and consequently the 
Permian age of the besimaudite zone itself, was definitely established 
by fossils found in the Negrone Valley near Viozéne, on the southern 
flank of Montgioie, by Zaccagna, and determined by Professor Portis 
of Pisa. Soon afterwards this discovery was confirmed independently 
by Squinabol and by Mazzuoli, both of whom found indubitably 
Upper Carboniferous fossils in the Bormida valleys already mentioned, 
where the Carboniferous strata are, moreover, anthracitic.! 
The distinguishing feature of the besimaudite zone, like that of the 
equivalent schists of the Apuan Alps, is its gneissiform character, 
but it also comprises, in upward progression, a variety of associated 
rocks. Thus, from a granular quartzose schist it passes into greenish- 
grey compact rock of porphyritic texture with large elongated 
felspar crystals up to 2 centimetres in length. Again it passes into 
nodulous gneissiform schist without felspar, or again into sericitic 
schist, and in places also assumes a granitoid structure, notably above 
Savona. There are also hornblende-bearing intercalations, simulating 
the aspect of pietra verde. In Monte Rocchetta occurs a large mass 
of reddish porphyritic quartzose rock with white mica crystals, 
which Zaccagna regards as intrusive porphyry, and which also occurs 
in Monte Abisso, close to the Col di Tenda Pass; but I am disposed 
to regard both these masses, which, moreover, lie in a zone, rather as 
Upper Permian, very similar to the red verrucano or sernifite of the 
Glarus Alps, a clastic rock which often has all the appearance of 
porphyry. 
_ The besimaudite zone is directly and conformably overlain by, and 
graduates into, a coarse conglomerate with white and reddish pebbles 
in a greenish, taleose matrix. This conglomerate or ‘anagenite’ is 
of considerable depth in the Montgioie range, and also occurs sparsely 
in the same position in the Apuan Alps. It represents the Upper 
Permian or Verrucano formation, and marks a transition from the 
latter to the Lower Trias. In my opinion, the porphyritic masses of 
Monte Rocchetta and Abisso already mentioned form part of it. It 
graduates, in its turn, into the conformably overlying Triassic series 
of quartzite, grey subcrystalline limestone, and calcareous schists, 
and these are overlain by banks of blackish, brecciform, marmiferous 
limestone with white calcite crystals, which is quarried near 
Villanova, at the northern base of the range, and is conspicuous in 
A. Portis, Boll. R. Com. Geol., vol. xviii, p. 417, 1887 ; L. Mazzuoli, ibid., 
p. 6; S. Squinabol, Giornale Scient. Genova, Fascic. Giugno, 1887. The 
survey of the Ligurian Alps eastward from the Montgioie range, surveyed by 
Zaccagna, was carried out concordantly by Mazzuoli and Issel, Boll. R. Com. 
Geol. 1884 et seq. 
