HISTORY OF THE MORVAN
MORVAN ROCKS UNITS
series and granite intrusions of the Morvan region are distributed
in three main units NE-SW oriented:
- In the nortern part the Settons massif
comprised a Medio-Variscan crystallophyllian basement (Chastellux
gneisses) intruded by Settons granite and then by Pierre-qui-Vire leucogranite
of respectivly Early-Middle Visean and Late Visean ages.
- In the central part the Morvan belt (faisceau du
Morvan) is composed of sedimentary and volcanic series deposited
from Late Devonian to Middle Visean intruded by Early-Middle Visean
Gien-sur-Cure la granodiorite; Late Visean acidic volcanic and
hypabyssal (granophyres : gh) rocks are locally cut by Folin
two micas granite.
- In the southern part the Luzy massif where
Medio-Variscan crystallophyllian basement (Montjeu gneisses) is
largely intruded by Early-Middle Visean Luzy granite and
Saint-Didier granodiorite and then by Late Visean Mesvres leucogranite.
Along its western border the Luzy granite cut and contact metamorphised
the Morvan belt volcano-sedimentary rocks. A similar disposition
occurs in the Saint-Léon horst, North of Bassin de Bert.
The Late Carboniferous and Permian Autun basin take
place between the Morvan belt and the Luzy massif.
The Late Carboniferous and
Permian volcano-sedimentary Blismes - Montreuillon
complex extends on Settons granite massif.