Like many islands in #MahoneBay, #NovaScotia, #OakIsland is a #drumlin - rock, sand, gravel and clay deposited by glaciers as the last ice age ended
about 12,000 years ago. Actually, the island is 4 connected drumlins.
Because #OakIsland is #drumlins, it may have layers of #gravel below sea
level which could explain the flood tunnel mystery. Searcher shafts might
just be intersecting sea water naturally flowing underground through porous gravel. #nspoli#NS @CurseOfOak @HISTORY#NovaScotia
Background info about the Oak Island mystery is at oakislandtours.ca.
More on the island's geology tomorrow....
#OakIsland's eastern bedrock, where the #MoneyPit is located, is #limestone
and #gypsum. They are soft rocks that often erode in groundwater, creating
natural tunnels and cavities. Some of the underground "workings" could be
naturally-occurring. #nspoli#NS @CurseOfOak @HISTORY
For example, in 1878 the Cave-in Pit was discovered on #OakIsland when oxen
plowing a field fell into a large hole. It might have been a
naturally-occurring sinkhole. #NovaScotia has many sinkholes caused by
erosion of soft #minerals like #gypsum. #nspoli#NS @CurseOfOak @HISTORY
For example, an e-car has 183 pounds of copper wiring in it because copper is used in every major component from the motor to the inverter and the electrical wiring. There is about four times more copper in an e-car than in a car with an internal combustion engine.
There are about 400 electric cars on Nova Scotia roads - a total of over 73,000 pounds of copper!
An electric car uses 25-50 grams of silver, so Nova Scotia’s 400 e-cars contain about 15,000 grams of it.
Concrete is a mixture of aggregates and paste. The aggregates are sand and gravel or crushed stone; the paste is water and portland cement. (The terms cement and concrete are often used interchangeably, but cement is actually an ingredient of concrete... #nspoli
...Cement is the glue that holds concrete together.)
Reinforced concrete means the concrete is poured over a frame, usually steel bars, that give the structure greater strength. #nspoli
The short answer is yes, sinkholes are real but no, they are not a major risk and should not prevent you from enjoying outdoor activities.
Most natural sinkholes are caused by groundwater naturally eroding rocks like gypsum, salt and limestone which are water-soluble. #nspoli
The water erodes the rock, leaving an underground cavern. Eventually, the weight of the rock and earth above the cavern causes the sinkhole to form. Sinkholes can form either gradually (i.e. a small depression appears and perhaps grows larger over time) or by sudden collapse.
The New Campbellton coal mine was opened in 1862 by Charles J. Campbell, a former Member of Parliament, Member of the Legislative Assembly and executive council member. The community had been named Kelly’s Cove but was changed to New Campbellton in 1862 in honour of Mr. Campbell.
A sample of New Campbellton’s coal was sent to the 1865 Dublin Exhibition and “was very favorably noticed by the Judges,” according to a report. #nspoli#cbpoli#novascotia#capebreton#nshistory
Mining built #NovaScotia! #Halifax was founded in 1749 and its first court house is reported to have been built by 1754 on the northeastern corner of Buckingham + Argyle streets. After the building burned in 1789, the courts were temporarily housed in various buildings. #nspoli
In April 1851 a bill to provide Halifax with a county court house was passed. Mr. H.G. Hill, a prominent #Halifax architect, prepared a plan for a wooden building.
However, since the records of the county, wills, deeds and other papers of public office were... #nspoli#novascotia
...to be stored in the court house, it was important that the building be fire-proof. Also, a number of serious fires in #Halifax in 1857 led to the passage of a bylaw that required large buildings be made of stone or brick, so Hill's plans for a wooden building were abandoned.
The Sullivan Creek #coal mine, before and after!
It's one of several mines reclaimed around #AlderPoint#CapeBreton in the late 1900s/early 2000s - examples of how mining makes temporary use of land and then land can be used other ways. #nspoli#cbpoli#novascotia@JaimeBattiste
The first mine in the area was the Scotia Mine, or #NovaScotia Steel & Coal Company No. 4 Colliery, on Toronto Road, which operated on the Sydney Main (Harbour) Seam from 1915 to 1921. #nspoli#cbpoli#novascotia@JaimeBattiste
Coal quality and structural issues (including water inflow) plague the Harbour Seam west of Florence so upon closure of the colliery, production on the Harbour Seam was limited to the Company’s No. 3 Colliery in Florence, which had opened in 1902... #nspoli#cbpoli#novascotia