Parc national du Gros-Morne

Brève description

Valeur exceptionnelle

Le Parc national du Gros-Morne est l’une des plus parfaites illustrations du phénomène de tectonique des plaques. Dans un espace relativement restreint on trouve des exemples typiques et concrets de forces monumentales de construction et de modification de la Terre dont la clarté, l’expression et la facilité d’accès sont uniques. Le bien présente le cours intégral des événements géologiques qui ont eu lieu lorsque l’ancienne marge continentale de l’Amérique du Nord s’est trouvée modifiée suite au mouvement de plaque par l’emplacement d’une vaste portion transférée de croûte océanique et de dépôts sédimentaires au niveau du plancher océanique. Le parc offre aussi une démonstration exceptionnelle de la glaciation dans un cadre insulaire. Les fjords, les chutes d’eau et les structures géologiques qui le caractérisent se conjuguent pour produire un paysage d’une beauté saisissante.

Critères

(vii) Le Parc national du Gros-Morne, environnement exceptionnel de nature sauvage composé de fjords d’eau douce spectaculaires à l’intérieur des terres et de promontoires érodés par les glaciers dans un cadre océanique, est un espace d’une très grande beauté naturelle.

(viii) Les roches du Parc national du Gros-Morne illustrent de manière collective et significative au niveau international le processus de dérive continentale le long de la côte est de l’Amérique du Nord et contribuent largement à enrichir la somme de connaissances et la compréhension de la tectonique des plaques et de l’évolution géologique des anciennes ceintures montagneuses. Dans les plateaux érodés par les glaciers et les fjords spectaculaires, la glaciation a rendu visibles les nombreuses caractéristiques géologiques du parc.

Description longue

[Uniquement en anglais]

Located on the western shore of the Great Northern Peninsula of Newfoundland, the park provides a rare example of the process of continental drift, where deep ocean crust and the rocks of the Earth's mantle lie exposed. More recent glacial action has resulted in some spectacular scenery, with coastal lowland, alpine plateau, fjords, glacial valleys, sheer cliffs, waterfalls and many pristine lakes.

The park comprises part of the Long Range Mountains on the Gulf of St Lawrence. The park includes coastal lowlands and an alpine plateau. The marine areas included in the park covers the inner portion of St Paul's Inlet, intertidal zones and estuaries. The shoreline features beaches, steep cliffs, and dune formations up to 30 m in height.

An upland alpine plateau with perched lakes, bare rock and valleys, covers a large proportion of the eastern central park. The serpentine hills in the south-west comprise ultra-basic igneous rocks, which, due to high heavy metal content, inhibit most plant life. A number of steep sided, glacial valleys cut through the Long Range scarp face, forming deep, oligotrophic fjords, with vertical cliffs up to 685 m high. A number of waterfalls are fed in the summer by snow-melt at higher altitudes.

The park is geologically diverse with areas of Ordovician sedimentary rocks, Precambrian granite and gneiss, Palaeozoic serpentinized ultra-basic rocks, gabbros, volcanic and Lower Palaeozoic sedimentary rocks. Exposed oceanic crust, mantle, a section of ancient Mohorovicic discontinuity, and other distinctive geological features are also found. There is also an unusually complete palaeotological sequence which has been proposed as the world stratotype for the Cambrian-Ordovician boundary.

There are up to 36 distinct vegetation types and communities, with some vascular species and bryophytes, representing about 60% of Newfoundland's insular flora.

The coast includes typical shoreline communities, active dunes with white spruce, and cliffs with prostrate spruce and balsam fir. The coastal plain further inland has a number of plant communities including a mosaic of sedges in meadows with American larch scrub. Black spruce dominates wet, oligotrophic sites and balsam fir is found in more protected and mesic areas. Tundra vegetation has developed on the plateau above this and varies from small areas of coniferous forest and stunted forest to bare rock.

Faunal diversity resembles an oceanic rather than continental-shelf island and is markedly reduced compared with the mainland. However a number of species scarce in Canada are found, including lynx, caribou and arctic hare. The more common marine mammals that can be observed from the park, albeit with a diminishing frequency in recent years include pilot, minke and finback whales and harbour seals.

The avifauna comprises arctic, boreal and pelagic species, with strays from mainland, the north-west Atlantic and Europe. The park is a significant breeding site for harlequin duck, blackpoll warbler, common tern and arctic tern, a nesting site for bald eagle, rock ptarmigan and American tree sparrow, and a stopover for migrating shore birds.

Anadromous Atlantic salmon and arctic char are found in park waters and also in permanent freshwater form in certain landlocked lakes on the Long Range Mountains.

There are a number of archaeological sites in the park and human habitation can be traced back to the Maritime Archaic Indians (4,500-3,000 years ago) and the Dorset Eskimos (1,800-1,200 years ago). Europeans settled the area from the late 18th century.

Source : UNESCO/CLT/WHC

Description historique

[Uniquement en anglais]

Established under a Federal/Provincial Agreement signed by the Governments of Canada and Newfoundland and Labradc on 13 August 1973. The same authorities amended this agreement on 18 May 1983, whereby approximately 9,300ha were returned to the province. The park is currently being formally established under the National Parks Act (Parks Canada, 1986). Inscribed on the World Heritage List in 1987.

Source : évaluation des Organisations consultatives