Geology, hydrology and geomorphology

Coastal Landscape

The Ungava Lowlands rise gradually from an elevation of 230 m to the Koroc River plateau. Unlike the rest of the park, this landscape is composed of rock surfaces polished by glacial erosion and several bodies of water. The largest among these, Lake Qarliik, is noteworthy for its pant-like shape. The coast is marked by active and perched beaches, the latter produced by the D’Iberville Sea. As well, the coast is swept by high tides, with ranges reaching 8 m at the mouth of the Koroc River. The unique landscape is composed of a variety of fresh, brackish and salt water environments for wildlife and plants.

Koroc River Valley

The Koroc River flows for 166 km. The river has its source in the Torngat Mountains and drains almost the entire territory of the park before emptying into Ungava Bay. The path of this sometimes tumultuous river is marked by the magnificent Korluktok Falls, which has an elevation of roughly 30 m. The wide Koroc River valley was carved by the colossal glaciers that once covered the region, and its many tributaries, including a number of suspended valleys, were also reworked during the last glacial period. Talus cones and accumulations at the foot of steep slopes are evidence of the freeze-and-thaw evolution of the landscape. For their part, numerous alluvial fans along the banks of the Koroc River indicate equally destructive events, such as extreme high-water levels, that have in the past reworked the fluvioglacial deposits stretched along the valley floor.

Excursions through the valley of the Koroc River with its sometimes rusty-coloured walls, produced by gneissic alteration, elicit a sense of grandeur that only grows with an ascent of one the parks summits, such as Mount Haywood. These summits reach above the Koroc River plateau and offer an awe-inspiring panorama of the immensity of this territory and the Koroc River’s multiple tributaries.

Torngat Mountains

At an average altitude of 760 m, the Koroc River plateau rises gradually to meet the Torngat Mountains. The formation of this mountain range began 1.8 billion years ago deep under the earth’s surface. The collision of the geological provinces known as Nain and Churchill produced peaks that stretched tens of thousands of metres high. Eroded over millions of years, the Torngat Mountains took their most recent form with the opening of the Atlantic Ocean to become the highest peaks in eastern Canada. The Torngat Mountains create a natural border, on the eastern edge of the park, with Labrador. The 1,646-m Mount D’Iberville dominates the extremely rugged mountain sector that is characterized by rocky ridges, boulder fields, sheer cliffs, as well as cirques that are sometimes cupped by glacial lakes.