Most of the park resides within what is called the
Ganderia Terrane, sometimes referred to as the Bras d'Or or Aspy Terrane. This was originally part of
Gondwana, referred to as peri-Gondwanan Terrane, and through
seafloor spreading, separated from Gondwana and collided with
Laurentia during the Salinic
Orogeny. The evidence of this collision, the closing of the
Iapetus Ocean and the formation of the
Iapetus Suture, is seen in the northwest part of the park where the Ganderia Terrane is connected with the Blair River
Inlier, itself a remnant of the Laurentia continental margin, referred to as peri-Laurentian Terrane. Other terrane collisions followed, including the
Avalonia Terrane during the
Acadian orogeny, and the
Meguma Terrane during the Neoacadian Orogeny. Then, between 340 and 300
Ma, Gondwana collided with Laurentia, forming
Pangea.
Rifting started about 200 Ma eventually forming the Atlantic Ocean. Along the
Cabot Trail between the park headquarters at Ingonish Beach and Ingonish, a 402 Ma old
Early Devonian granodiorite is exposed, the Cameron Brook
Pluton, while the Keltic Lodge, on Middle Head, sits on a 493 Ma old
Early Ordovician granite and a 550 Ma old
Neoproterozoic diorite. The beach in front of Freshwater Lake is a classic
shingle beach, a
barrier beach with
boulders well rounded and polished from wave action.
Glacial debris is evident along the trail at the north end of the lake. A similar bar cuts across Ingonish Harbor. A Middle to 375 Ma
Late Devonian granite is seen along the Cabot Trail between Ingonish and where it leaves the park near South Harbor, while a 403 Ma
Early Devonian orthogneiss is exposed at Neils Harbour northward. From Cape North, the Cabot Trail follows the
Aspy Fault southwards, where the
Early Carboniferous Windsor Group and Horton Group
outcrops, until it reenters the park at Big Intervale. These groups of rocks consist of
limestone,
mudstone,
anhydrite,
gypsum,
halite,
siltstone,
fluvial sandstone,
shale, and
conglomerate. The Windsor Group is also exposed at Ingonish and Ingonish Beach. The Cabot Trail then follows the Grande Anse River westwards, with exposed Horton Group until it reaches the coast at Pleasant Bay. This is the location of the 364 Ma
Late Devonian granite of the Pleasant Bay Pluton. Moving south along the trail, the 433 Ma
Ordovician-Silurian Belle Cote Road orthogneiss is encountered, followed by another granite (Proterozoic-Devonian in age). As the trail loops west to follow the coastline, rocks of the 439 Ma Ordovician-Silurian Jumping Brook Metamorphic Suite are exposed. This suite consists of
metamorphosed siltstone,
wacke, conglomerate,
arkose, and minor
rhyolite. In the midst of this suite may be found the 379 Ma Devonian granite of the Gillanders Mountain Pluton. The trail encounters a 439 Ma
Cambrian granite before it exits the park at La Rigoueche. == Trails ==