It is a young volcano
of about 8,000 years, a period during which this well-known
Strombolian cone was formed. This youth explains the freshness
of its shapes and makes it a magnificent
structure, very visited today. From a volcanological
standpoint, it is the result of a complex
and turbulent history, whose fallout went far beyond
Clermont-Ferrand. Moreover, it is a double-crater system, which
does not appear clearly due to the fact that the original structure
suffered during the final episodes.
A crater of impressive
dimensions
A complex story
This illustrates that this Chain of volcanoes is
in constant change, particularly
the transformation of the magmas contained in the underlying
reservoirs, a transformation that will
determine the eruptive dynamism.
Originally, a few basaltic Strombolian
cones of modest height were aligned in the place of the modern
Pariou. Then a succession of trachytic
explosions from a viscous magma (trachy-andesite)
and highly charged with gas tore apart the existing edifices.
From this cataclysm, a ring of pyroclastic
deposits of trachytic nature was formed.
It was during this phase that
the effectswere
very significant on the neighboring regions, as the
resulting pyroclastic flows almost reached the gates of Clermont-Ferrand,
and the fallout went much further.
This ring, completed by a crater
collapse following any volcanic explosion, will contain a small
lava lake fed by the conduits. Under pressure, the northeast
edges of the ring will give way, allowing
the lava to flow eastward. The outflows will reach
Chamalières, Durtol, and Nohanent. This lava, of trachy-andesitic
nature, with a composition close to Volvic lava, was once exploited.
The current cone marks the (provisional?)
end of the activity prevailing within the trachytic crater.
Architecture du système
Pariou (vue du puy des Goules)
Mais l'image Lidar
d'aujourd'hui est bien plus explicite ! (Source Géoportail)
The crater: undoubtedly
the deepest in the Chaîne des Puys: 92 meters deep, 300
meters in diameter
Visit
It is called the
Auvergne Vesuvius. This
reference comes from the fact that it resembles the famous Italian
volcano, albeit modestly and only in terms of its morphology
– the pyroclastic ring symbolizing the "Somma" and the current
cone representing the cone of Vesuvius embedded in the Somma.
Like the latter, it is of course very
visited. The starting point is at the Col des
Goules.
The designated
trails leading to the summit reveal the different
aspects of the volcano: the pyroclastic
ring, the depression of the former "lava lake," and of course
the terminal cone.
To
preserve the soil and keep the site in good condition, one does
not descend into the crater.
As at the summit of all chain
volcanoes, the viewpoint is unique. The neighboring volcanoes
also offer an interesting view of the Pariou system, notably
from the Puy des Goules.
It is a young volcano
of about 8,000 years, a period during which this well-known
Strombolian cone was formed. This youth explains the freshness
of its shapes and makes it a magnificent
structure, very visited today. From a volcanological
standpoint, it is the result of a complex
and turbulent history, whose fallout went far beyond
Clermont-Ferrand. Moreover, it is a double-crater system, which
does not appear clearly due to the fact that the original structure
suffered during the final episodes.
