CHAPTER XII. 
Geological monuments of the older Pliocene period — Subapennine formations — 
Opinions of Brocchi — Different groups termed by him Subapennine are not 
all of the same age — Mineral composition of the Subapennine formations — 
Marls — Yellow sand and gravel — Subapennine beds how formed — Illustra- 
tion derived from the Upper Val d'Arno — Organic remains of Subapennino 
hills — Older Pliocene strata at the base of the Maritime Alps — Genoa — Savona 
— Albenga — Nice — Conglomerate of Valley of Magnan — Its origin — Tertiary 
strata at the eastern extremity of the Pyrenees. 
OLDER PLIOCENE FORMATIONS. 
We must now carry back our retrospect one step farther, 
and treat of the monuments of the era immediately antecedent 
to that last considered. We defined in the fifth chapter*, the 
zoological characters by which the strata of the older Pliocene 
period may be distinguished, and we shall now proceed at once 
to describe some of the principal groups which answer to those 
characters. 
Subapennine strata. — The Apennines, it is well known, are 
composed chiefly of secondary rocks, forming a chain which 
branches off from the Ligurian Alps and passes down the 
middle of the Italian peninsula. At the foot of these moun- 
tains, on the side both of the Adriatic and the Mediterranean, 
are found a series of tertiary strata, which form, for the most 
part, a line of low hills occupying the^space between the older 
chain and the sea. Brocchi, the first Italian geologist who 
described this newer group in detail, gave it the name of the 
Subapennines, and he classed all the tertiary strata of Italy, 
from Piedmont to Calabria, as parts of the same system. 
Certain mineral characters, he observed, were common to the 
whole, for the strata consist generally of lightbrown or blue mark 
covered by yellow calcareous sand and gravel. There are also, 
* Above, p. 54. 
