The Récif fossile de Marchon - Christian Gourrat Regional Nature Reserve (RNR284) is a Regional Nature Reserve located in

Auvergne-Rhône-Alpes Auvergne-Rhône-Alpes (; AURA) or ; or ; . is a Regions of France, region in southeast-central France created by the 2014 territorial reform of French regions; it resulted from the merger of Auvergne and Rhône-Alpes. The new region came into e ...

. Established in 2015, it spreads over and protects a limestone

outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth and other terrestrial planets. Features Outcrops do not cover the majority of the Earth's land surface because in most p ...

bearing fossils from the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

era.

Localisation

The territory of the natural reserve is located in the

Ain Ain (, ; ) is a French department in the Auvergne-Rhône-Alpes region, Eastern France. Named after the Ain river, it is bordered by the Saône and Rhône rivers. Ain is located on the country's eastern edge, on the Swiss border, where it ...

department, on the town of

Arbent Arbent () is a Communes of France, commune in the Departments of France, department of Ain in the Auvergne-Rhône-Alpes region of eastern France. The commune has been awarded two flowers by the ''National Council of Towns and Villages in Bloom' ...

near the city of

Oyonnax Oyonnax () is the second most populated commune in the Ain department in the Auvergne-Rhône-Alpes region in eastern France. Oyonnax lies in a valley of the Jura Mountains in the far north of Ain. It is near the Parc naturel régional du Hau ...

. Its reduced surface makes it the second smallest natural reserve of France..

History of the site and reserve

The site was discovered in 1996 by Christian Gourrat, a naturalist from Oyonnax. Initially established as a Voluntary Nature Reserve under the name of ''Forêt de Marchon Natural Reserve'', it is now registered at the regional inventory of geologic sites.

Ecology (biodiversity, ecological interest, etc.)

The site is reduced to a limestone outcrop in the Marchon forest. It bears fossil animals from the

era (140 My), particularly

rudist Rudists are a group of extinct box-, tube- or ring-shaped marine heterodont bivalves belonging to the order Hippuritida that arose during the Late Jurassic and became so diverse during the Cretaceous that they were major reef-building organis ...

s. For several species, the reef represents the '' locus typicus''. The local forest is mainly composed of

beech Beech (genus ''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to subtropical (accessory forest element) and temperate (as dominant element of Mesophyte, mesophytic forests) Eurasia and North America. There are 14 accepted ...

and

spruce A spruce is a tree of the genus ''Picea'' ( ), a genus of about 40 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ecosystem, boreal (taiga) regions of the Northern hemisphere. ''Picea'' ...

Touristic and educational interest

The reserve is open to the public. Any samplings are forbidden.

Administration, management plan, regulations

Tools and legal status

The natural reserve was established after a deliberation of the Regional Council of 06 March 2015.

References

{{reflist Protected areas established in 2015 Regional natural parks of France Geography of Ain Tourist attractions in Ain Geologic formations of France Cretaceous Europe Limestone formations Hippuritida Fossiliferous stratigraphic units of Europe Paleontology in France Ain