Parks / Québec
Archipelago National Park
The most extraordinary feature
of the islands is their dramatic topography.
Limestone- based, unlike the exposed Canadian
Shield of the mainland, the bedrock has undergone
repeated cycles of lifting and submersion, with
the latest rising-up occurring at the end of
the last glaciation. During the last major ice
age, 20 000 years ago, the Mingan Archipelago
was covered by 2.5 kilometres of ice. As the
glaciers began to melt, the ocean level rose
covering the islands with 85 metres of water.
Very slowly the islands lifted until about 7000
years ago when they broke the surface. With
the shifting of the earth's crust, the limestone
bedrock which came to the surface as a huge
plateau soon eroded to form splits and cracks.
Further water erosion split up these rocks to
form the archipelago. On the south side of the
islands is a complex network of arches and grottoes
that contain a rare collection of fossil remains
of over 200 marine organisms, a treasure trove
of major scientific significance. Here is also
found the largest concentration of monoliths,
or sea stacks, in Canada. Created from friable
rock more than 450 million years old, they are
still being eroded by waves, changing sea level,
wind and severe weather. The north side of the
islands is characterized by about 45 kilometres
of cliffs rising to a maximum of 15 metres reminiscent
of arctic landforms, while the interiors support
boreal forest on their gently inclined slopes.