Solid mass of the Greenhouse

The massive of the Greenhouse is a granitic solid mass French located in the department of the the Jura between Dole and Besancon.

The maximum altitude of the solid mass of the Greenhouse is approximately 400 meters. Primarily covered of forests (beech, conifers), it is the only granitic solid mass of the department of the Jura.

Geology

The old massive of the Greenhouse is a Horst of crystalline base lengthened according to a north-eastern axis - south-west, which bores the sedimentary cover Mesozoic préjurassienne. The strange position of this granitic small island, between the the Vosges and the Massif Central, would be due to the existence of important faults hercyniennes energy of the basins of Blanzy and Autun until the south of the Vosges.

The rocks which level in the solid mass of the Greenhouse are mainly plutonic (Granite monzonitic, Pegmatite) and metamorphic (Gneiss, Mylonite). In the North-West of the solid mass, a fault is also covered with volcanic rocks ( eurite of the careers of Moissey, a Ignimbrite) and sedimentary dated from the Permien.

The top of the solid mass is covered with a sandstone arkosic Trias resting in discordance on the crystalline base. The erosion of this sandstone gives rise to cavities such as the Grotte of the Hermitage. This sandstone with coarse grains was used as of the Neolithic to manufacture polishing machines and grinding stones with grains then at the more recent times for the clothes industry of grinding stones of mill.

Inheritance

References