GEOLOGICAL HISTORY OF THE MORVAN

MORVAN ROCKS UNITS

Paleozoic volcano-sedimentary 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. 

Blismes-Montreuillon Basin Chastellux Gneisses Montjeu Gneisses Autun Basin Mesvres Leucogranite Pierre-Qui-Vire Leucogranite Dévonian Settons Granite Luzy Granite Tournaisian Tournaisian Late Visean Late Visean !! clickable map

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.


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