Geological guide to Newfoundland and Labrador

Stops Of Interest: Central Newfoundland, Baie Verte Area
  1. Virginite and serpentine, Route 410
  2. Asbestos mine, Baie Verte
  3. Dorset Paleoeskimo soapstone quarry, Fleur de Lys
  4. Tilt Cove copper mine

1. Virginite and serpentine, Route 410

The ultramafic rocks found on the Baie Verte Peninsula contain an unusual set of alteration minerals, often highly coloured and ornamental. Virginite is the local name given to altered ultramafic rock that is reddish-brown on weathered surfaces and emerald green, streaked with white quartz and carbonate, when freshly broken. It outcrops on both sides of the road about 45 km north of the TCH junction, just north of the Westport junction. Exposure is best on the east side. This decorative rock is often polished to make clock faces and ornaments.

Virginite was formed when ultramafic rocks were chemically altered by hot fluids flowing through a nearby fault zone. The bright green mineral is a type of mica that contains the element chromium. The chromium was originally in little black crystals of chromite, some of which can still be seen in the rock.

About 200 m farther north, on the west side, is a slippery green slope of serpentine, another ultramafic alteration mineral. Serpentine is apple green in colour, and has a waxy lustre; when alteration is more severe, this mineral becomes asbestos, the fibrous product mined north of Baie Verte. The slope beside the highway is made up of broken fragments; when you break a piece, the new fragments are flat and slippery.

2. Asbestos mine, Baie Verte

The open-pit asbestos mine in ultramafic rock is a few kilometres north of the town of Baie Verte. The asbestos was formed by chemical alteration when hot fluids flowed through fractures in the ultramafic rocks.

The open pit may be seen on the east side of the highway a short distance beyond the access road to the Terranov Mining Corporation plant. Tailings from the present operation will be used to gradually fill the disused pit. For a tour of the new wet-process extraction facility, arrange in advance by phoning (709) 532-4862.

3. Dorset Paleoeskimo soapstone quarry, Fleur de Lys

At the north end of the community of Fleur de Lys is an archæological display at the site where Dorset Paleoeskimos quarried soapstone blocks for bowls and lamps, between 1100 and 1600 years ago. The raw blocks were probably traded to more distant groups lacking a source of the material, making this one of the earliest commercial mining ventures in the world.

Soapstone contains the soft mineral, talc, which is an alteration product of ultramafic rocks, and is used in making talcum powder. Soapstone is also soft and is easily shaped or carved, which has made it useful to Stone Age peoples and modern artists alike. Warning! Protected site. Hammering is not permitted.

4. Tilt Cove copper mine

To reach Tilt Cove, take the signposted gravel road south from Route 414. The site shows ample evidence of its past successes and failures as a mine. Riddled with old pits and other openings, the area bears little resemblance to the natural scene that existed before 1864. On the left side of the road descending the hill into the cove is the site of the 1890s smelter; waste piles and discarded conical molds of slag remain from that early phase. (See Island of Newfoundland map for mining history).

The original narrow passage to the interior cove (called Winser Lake after its first settlers) has been almost entirely blocked off in the course of mining activity. Cliffs of basalt and diabase streaked with rusty gossan surround the cove. The main minerals that were mined from the basalt, in a warren of large and small pits and workings, were pyrite and chalcopyrite; you may also see magnetite, sphalerite and pyrrhotite. It is possible to pick up abundant sulphide samples around the base of the walls, particularly on the east side out toward the opening to the sea, and around the old loading wharf.

Warning! Many old mine openings still exist in the hills surrounding the cove. Use extreme caution if exploring in these hazardous areas.

The set of rocks found at Tilt Cove (basalt, diabase, gabbro and ultramafic rock) is called ophiolite. It is a slice of oceanic crust which was up-ended when the Iapetus Ocean closed in Ordovician time (see Plate Tectonics panel).

From the wharf, a good view can be obtained of basalt pillow breccia in the lower part of the cliffs on the north side of the inlet. Above the breccia are red-brown Ordovician sedimentary rocks, including chert, shale and siltstone. A grey-green, younger dyke intrudes all of the older rock types.

The hills backing the cove consist of purplish and buff Silurian basalt, volcanic ash and sandstone. An unconformity separates these rocks from the ophiolitic rocks below. The unconformity is almost coincident with the road along the back of the cove.

This series of web pages provides an introduction to the publication below, which can be ordered from the Geological Association of Canada Geological Association of Canada

Newfoundland and Labrador Traveller's Guide to the Geology

Edited by: S. Colman-Sadd and S.A. Scott, 91 pp. + map, 1994

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