To see the schist, take the Grand Bay West road off the TCH and continue to just before the bridge to Grand Bay East; turn west on a short paved road, and drive beyond the houses and pavement for about 400 m to the sand dunes. Park there and walk west toward the beach, then turn left (south) on or above the beach to a point where the schist outcrops. A barn-like building is built near the point; please respect private property.
In the beach outcrop, the schist contains bladed networks of shiny black hornblende, bluish kyanite crystals up to 1 cm long, red garnets up to 0.5 cm in diameter, staurolite, pyrite, chalcopyrite, and white and black mica. White quartz veins are broken apart and mineral bands are folded.
A less varied suite of minerals can be seen in outcrops back at the sandy beach just beyond the end of the pavement.
Drive into Cheeseman Park, a few kilometres north of Port aux Basques, and park at the south end of Little Barachois Pond. To make the tour across the fault zone, walk east along the disused railbed toward Port aux Basques. The distance to the far side of the zone from the car park is about 2.5 km.
Before you set out along the railbed, walk along the shore to the right to see the Cape Ray granite; this is a coarse-grained granite containing large feldspar crystals and inclusions of altered dark gneiss. Closest to the pond (and the influence of the fault), the granite is severely squeezed and stretched. As you move west, away from the fault, this deformation decreases. Now walk east along the track.
About 200 m past the bridge, walk down to the shore on the east side of Jerret Point (see sketch map). Here basalt lava flows, pillows and breccia, and gabbro sills have been folded and stretched in a northeasterly direction, parallel to the Cape Ray Fault.
On the western side of the next point to the east (Windsor Point) is a folded sequence of sedimentary rocks: conglomerate interbedded with volcanic ash, sandstone, black shale and siltstone. The conglomerate contains pebbles of volcanic rocks, quartz, siltstone, black shale and granite. As with the other rock types, deformation increases toward the southeast, until the conglomerate has been completely ground up and transformed into a pinkish, fine-grained rock called mylonite. Pinkish to beige and green mylonitic rocks are exposed for more than 200 m along the shore, and indicate the most extreme deformation within the fault zone.
Cross the pond inlet on the railbed bridge (see sketch map); on the shore just beyond the bridge is evidence that we have passed to the other side of the fault. The rock here is less deformed, but is still strongly foliated. It is a dark grey to black gneiss, which was originally formed by metamorphism of sandstone.
Rocks on the northwest side of the fault were once part of the Laurentian continent, whereas the gneiss on the southeast side originated at the edge of the Gondwanan continent. Collision of the two ancient landmasses has brought the unrelated rock units together and caused the extreme deformation seen along the fault zone.
Where the road crosses the Little Codroy River south of Tompkins, stop and look southeast towards the mountain front. You are facing directly up one of the hanging valleys. Note the U-shape of the valley, and the lip which has a small notch eroded by the modern brook. There are several more hanging valleys to the north and south.
Turn off the TCH at Route 405, heading for St. David's and Highlands, and turn left at St. Fintan's. Continue on this paved road, turning left at the T-junction on the coast (6.2 km); after a farther 5.9 km, the road turns to gravel. Drive 2.5 km to where the skull of a large whale rests in the grass on the left hand side, at the crest of a small hill. About 100 m farther on, a trail leads to the right through tuckamore spruce. Park and walk down a steep brook bank to the beach. Warning! The bank is very steep, sometimes slippery, and the path is narrow. You are passing finely laminated, steeply dipping red and green shales containing yellow cubes that have replaced original salt crystals or tiny cubic cavities from which the salt has been dissolved.
On the beach, to the left and offshore are black limestone stacks where cormorants are often perched. This reef limestone contains fossil brachiopods, and was originally capped by whitish gypsum, which now lies in slumped masses on the beach. The gypsum is finely laminated, and waves have eroded its base. Solution cavities contain large, clear gypsum crystals, several centimetres across.
Farther south, at low tide, you can reach another limestone exposure, which contains crystals of barite and the copper-bearing mineral, chalcocite.
North of the brook where you reached the beach is an exposure of red sandstone and siltstone. A large fault has disrupted the layers, and some of them are overturned.
These sedimentary rocks were all deposited in a large shallow sea, which stretched out into the Gulf of St. Lawrence. The gypsum layers and salt crystals were formed as the seawater evaporated. The sea was overlooked by highlands of the Indian Head Range and the Port au Port Peninsula to the north, and the Long Range Mountains to the east.
Silurian sedimentary and volcanic rocks were deposited in several narrow basins in central Newfoundland. Most of the basins trend northeasterly and were formed by faulting.
Examine the granite in the boulders on the right side of the road just before the road descends into the pit. The boulders are formed of grey Silurian granite with large, white feldspar crystals. In some boulders, coarse-grained granite forms veins in finer grained granite which therefore crystallized slightly earlier.
Also examine the rusty brown rock. This is the Ordovician sedimentary country rock (sandstone), which has been metamorphosed by the heat of the granite. The main metamorphic mineral is biotite, which causes a dark brown sheen on some surfaces.
Warning! Do not approach the cliffs. There is danger of falling rocks, and nothing that cannot be seen in the safe parts of the quarry.
The cliff on the right of the main part of the quarry shows granite sills intruded between sedimentary rock layers. These are in turn intruded by white veins which have coarse-grained granite pegmatite borders and fine-grained centres. Some of the veins contain the same minerals as the main granite, but others have less common minerals as well. In the floor of the pit, at the mouth of its main part, are fine-grained white granite veins with tiny red round crystals of garnet, granite pegmatite boulders with long black crystals of tourmaline and rare, greenish crystals of beryl (emerald).
Fox Point, at the southern tip of the park, is composed of an intrusion breccia, which contains blocks that are much older than the Silurian Burgeo granite. To reach Fox Point, park in the parking area and walk to campsite 14, the start of the trail to Cow Head. Follow this trail, turn left at Russell's Path, then walk south along the beach to Fox Point. The best exposures are on the south side of the point.
The intrusion breccia contains blocks of dark gneiss up to 2 m in diameter in fine- to medium-grained grey granite. The blocks are pieces of country rock that were broken off the walls of the magma chamber and carried along by the intruding granite. You can see gneissic banding and folding in some of them.
Newfoundland and Labrador Traveller's Guide to the Geology
Edited by: S. Colman-Sadd and S.A. Scott, 91 pp. + map, 1994