RCAF Enclave EarthCache

RCAF Enclave

Cole Harbour

Legend has it that previous visitors knew of Cole Harbour, perhaps as a sheltered haven, as a Norse axe was discovered here during the 1800’s; however, its whereabouts are since unknown. The local native tribe of Mik’maq also were aware of the location, as they identified it as “Wonpaak”, meaning “still water”. Legend also has it that during or prior to the early days, pirates or privateers have buried treasure inside the harbour entrance. The harbour itself is quite sheltered from the ocean and winds, and was often sought as a haven during gales and bad weather. Marine guidance to the harbour was by two range lighthouses for approach from the bay, and a single lighthouse near Dort’s wharf to guide craft into the harbour.

While it is uncertain when or for whom it was named, Cole Harbour was first settled in 1817 by George Tanner and William West. Like Tor Bay, Whitehead, Country Harbour, etc., the name Cole Harbour seems to be older than the settlement. Dr. A.C. Jost suggests it may have been named for Captain Cole of the sloop William which was captured in the vicinity by a Spanish privateer in 1719. Another theory is that it was named for an early fisherman who based his operation here.

R.C.A.F Station - Queensport/Cole Harbour

There were at least 8 other markers within 8 kilometers of this marker, measured as the crow flies. They operated during a three year period (1942-1945) where approximately 180 officers and men operated, serviced, or otherwise gave support to a radar unit on this site. Air-defense radar stations were first established in Canada along the Atlantic and Pacific coasts in 1942, but were dismantled following the defeat of Germany and Japan in 1945. Planning for radar stations on the East Coast of Canada had started in 1940. Site selection had been completed, equipment ordered and on site construction completed to enable the first stations to become active by mid 1942. The last of the stations would become operational in late 1944. The role of these stations varied depending upon the equipment at each location. They included chain home low - early warning radar (CHL), microwave early warning radar (MEW), ground controlled intercept radar (GCI) and high-flying early warning radar (TRU).

Geology

Devonian granite began as molten magma. Molten magma is found under the surface of the Earth. When it breaks the surface, as in a volcanic eruption as lava or through decompression from tectonic plate separation. As the magma slowly cooled several kilometers beneath the surface, large crystals of glassy quartz, dark mica and pink, white or buff feldspar were created. Uplift, weathering and erosion throughout the last 380 million years have removed the overlying rock.

Granite Colours

Specifically, granite is made from molten igneous rock that cooled within a crust. As it cooled, crystals formed from the minerals within it. The size of these crystals – known as grains – is proportional to the speed at which the rock cooled. As well, since the rock cooled without having been expelled from a crust, the resulting grain make-up is not homogeneous. That’s what gives granite its many hues.

If the granite formed with a lot of amphibole and quartz it would tend to be a black and white speckled colour. If it formed with a lot of potassium feldspar it will likely be a salmon pink one. Granite formed mostly of quartz alone will typically be a milky white colour. A lot of amphibole, on the other hand, will result in a black or dark green colour.

White granite is composed primarily of quartz, responsible for the milky white colour, and feldspar, responsible for the opaque white one. If the granite contains small black speckles these are likely due to small amphibole grains. Pink granite is formed from an abundance of potassium feldspar. Should it contain speckles of a milky colour these would be due to quartz. Black speckles would be from amphibole and opaque ones from feldspar.

Black and white granite would likely have equal parts amphibole, quartz and feldspar.

Red granite is similar to pink but with the potassium feldspar having more of a reddish colour. The red shade may also derive from iron oxide in the rock.

How enclaves are formed geology?

In geology, an enclave is an aggregate of minerals or rock observed inside a larger rock body. Micro-granular enclaves in felsic plutons result from the introduction of mafic magma into the magma chamber and its subsequent cooling following incomplete mixing.

Mafic Enclaves

Mafic enclaves are volumes of rock surrounded by a host rock of related but distinct composition and of different classification. The igneous rock is trapped deep inside the earth millions of years ago where it was in a liquid state and once it came to the service or near service it cooled quickly trapping other rocks inside it. The trapped stones are different from the host rock and can be seen with the naked eye.

Enclaves are inclusions, typically in the 1 cm to 1 m size range, and may be round to angular in shape and in plutonic rocks are usually finer grained than the host. The degree of mixing just depends on what happened at the time it occurred.

Dark spots, of variable sizes and shapes, break the homogeneity of granite. These enclaves that can be of 3 types and different aspects: 1) the host rocks of fragments crossed by granite: these are xenoliths; 2) original magmatic enclaves resulting from the immiscibility of magma of different chemical composition, like a mixture of oil and vinegar; or 3) unmelted residue refractory to the base of the continental crust (various minerals).

To log this Earthcache visit the viewing location.  Please answer the following questions and send in a timely manner to my geocaching profile or email. Answers not received will result in deleted logs.

Questions:

1. How many enclaves on the Back vs the Front?

2. On the front upper left, how big is that enclave (length x width) and it’s shape?

3. Explain how the smaller rocks got into the larger one?

4. Why didn’t the smaller stones melt too?

5. Post a picture in your log with a personal item or hand in picture to prove you were there.

[REQUIRED] In accordance with the updated guidelines from Geocaching Headquarters published in June 2019, photos are now an acceptable logging requirement and WILL BE REQUIRED TO LOG THIS CACHE. Please provide a photo of yourself or a personal item in the picture to prove you visited the site.