Maritimes - Summer 2008
July 5 - 25, 2008
Day 12 - july 16
five islands, South Maitland Tidal Bore, gypsum, hayes cave & renfrew gold
East Milford Gypsum Quarry
This is the way to learn about Canada's natural resources. Not by looking at a map of Canada with hundreds of little symbols and trying to remember that the triangle in Nova Scotia represents gypsum mining. What an impressive sight.
From the East Milford Fossil Quarry earthcache description:
"This EarthCache is located at a viewpoint above the East Milford Gypsum Quarry. The huge hole is the largest gypsum mine in the world! In addition to gypsum, the mine has produced an unexpected economic output, a cottage industry of mastodon statues.
Here and there across Nova Scotia, white gypsum cliffs rise among the green spruce. The soft white rocks can be scraped with your fingernail or broken in your hands. Gypsum, a soft sedimentary rock mineral, consists of calcium sulphate chemically combined with water (calcium sulphate dihydrate, or CaSO4.2H2O). It is commonly white or light brown in colour, and forms through the evaporation of salt waters. Nova Scotia's major gypsum resources are located on the northern mainland and Cape Breton Island in a geological unit called the Windsor Group. These deposits were created 350 to 335 million years ago, when an inland sea became very "salty" due to evaporation in a hot dry climate. Large amounts of gypsum and anhydrite (calcium sulphate), salt (halite-sodium chloride) and limestone (calcium carbonate) were precipitated from the dense "salty" sea water. Huge deposits of limestone, salt and gypsum/anhydrite were created by evaporation from these ancient seas.
Mining of these thick gypsum deposits has made Nova Scotia the world's most productive gypsum mining region. In the quarry, resting on gypsum bedrock, is a record of Pleistocene sediments dating back 209 ka (ka = 1000 years ago). There was a major ice advance approximately 209 ka, followed by a lengthy warm period called an interglacial. During this period, which lasted from 125 to 79 ka, the climates in Nova Scotia fluctuated from as warm as southern Georgia, USA, to as cold as northern Quebec. During the last cold phase of the interglacial, mastodons roamed Nova Scotia, and one fell in some muck in a sinkhole and died. Later, several glaciers passed over the quarry and the mastodon protected in the sinkhole, covering it with 30 m of glacial deposits. The National Gypsum Company stripped off these glacial deposits to reveal the beast. In 1991, Stanley McMullin, a grader operator, noticed a tusk in some fill that he was excavating from a sinkhole. Scientists from the Nova Scotia Museum eventually uncovered the nearly complete remains of an adult and juvenile Mastodon ( Mammut americanum). These include skull, (with tusk and teeth disarticulated), scapula, thoracic vertebra, ribs and femur bone fragments (Grantham and Kozera-Gillis, 1992). A few pollen samples from the sinkhole organics revealed a homogenous conifer-dominated assemblage, consistent with a cool boreal forest environment. Wood ( Pinus banksiana) found near the mastodon bones was dated at >51 ka . "
On the way to the quarry we came to (yet another!) construction area. We were rather puzzled by this truck that led us through the short, perfectly straight, uncomplicated, self-evident (need I go on?) single lane segment of highway. Cause otherwise we would have gotten lost...?
Getting hungry, we stopped at a bakery for what else... mud cookies!
At the National Gypsum Canada Ltd. quarry in East Milford, Halifax County.
This is the most productive gypsum mine in the world,
with annual output around 3 million tonnes.
Sammy with the East Milford Quarry in the background.
Two different outcrops of gypsum.
The grey, very granular and compact gypsum is called alabaster,
whereas the crystal gypsum is called selenite.
Following the gps we ended up driving through part of the mine property by mistake and ended up on this interesting bridge that is used both by trains and cars.
Having learned about the mastodon bones that were discovered in this quarry in 1991 when one of the workers found a tusk, the mastodon statue seen here from the highway made a little more sense.
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