Most of the rock used in construction comes from quarries. Quarries are places where sand, gravel and stone are excavated for building materials. Quarries are very important in our lives. In North America, we use up about 500,000 kg of stone, sand, gravel and cement per person in a lifetime. That is a HUGE amount. Of course you don't use it all up, nor do you use it at home. The reason the number is so high is because we all use roads, airports, schools, buildings, and anything else that needs crushed stone.
We are fortunate that in Canada that we have many good sources of building stones and aggregate – namely sand, gravel and crushed rocks.
"Every year, the people of Ontario consume approximately 173 million tonnes of aggregate. That is about 1 truck load for every man, woman and child in the province! We all share in the responsibility for the demand for aggregate materials. Through responsible land stewardship, innovative operations, creative rehabilitation and responsible marketing, the aggregate industry is minimizing the impacts and maximizing the benefits that aggregates provide to the province of Ontario." Source: J.C. Duff Sand & Gravel
Many quarries for crushed stone use limestone which is a sedimentary rock. Not only can you find fossils in limestone, but mineral specimens are also found. Another word for crushed stone is aggregate. Here in Ontario, there are many working quarries that welcome visits by school groups. The Ontario Stone, Sand & Gravel Association keeps an up to date list of companies that offer school tours at http://www.ossga.com/tours_open_to_the_public/
Since the rock is blasted and crushed into smaller pieces, quarries are a great place for Rockhounds because a lot of the hard work of breaking up the rock is already done. The Mining Act has rules about quarries because of safety issues. Quarries are all on private property and may not be entered without permission. If you are a member of a rock club, are over 19 years of age, and a member in good standing with CCFMS then you can also visit some quarries on planned field trips. Over the years, different quarries have welcomed rockhound groups belonging to Rock & Mineral Clubs. Some that we have visited in the past are:
- Dundas Quarry Lafarge Dundas, Ontario
- Lincoln Quarry/Beamsville Quarry Nelson Aggregate Co. Beamsville, Ontario
- Burington Quarry Nelson Aggregate Co Burlington, Ontario
- Coldwater Quarry Lafarge Coldwater, Ontario
- Hilltop Quarry Georgetown, Ontario
- Duff Quarry J. C. Duff Sand & Gravel Limited Limehouse, Ontario
- Milton Quarry Dufferin Aggregate Co. Milton, Ontario
- Flamboro Quarry, Dufferin Aggregates, Dundas, Ontario
- Mara Quarry, James Dick Aggregates, Beaverton, Ontario
- Marmaraton Iron Mine Marmora, Ontario
Aggregate is what pieces of rocks that have been blasted is called. The gravel you see in driveways & at the side of the road are aggregate. Sometimes you won't see aggregate because it has been mixed with cement to make concrete - the grey "stuff" that sidewalks, buildings and curbs are made of. Aggregate can also be mixed with tar and other ingredients to make asphalt - the black surface the school yard is paved in.
Quick Facts: Aggregates source: Ontario Stone, Sand & Gravel Association (OSSGA) http://www.apao.com/
- The average school requires 13,000 tonnes of aggregate (almost 650 truckloads)
- An average brick home uses 440 tonnes of aggregate (22 truckloads)
- One kilometer of a six-lane road uses 51,800 tonnes of aggregate (2,590 truckloads)
- A typical large office building uses 16,000 tonnes of aggregate (800 truckloads)
Although wood, straw and mud is used for houses in some parts of the word, most cities today are built of stones and metal (minerals). Many rock & minerals are used to make buildings. Many buildings built out of stone over 2000 years ago can still be seen in places where ancient civilizations existed like Rome, Greece, Peru and Central America.
- Concrete (sand, gravel), steel (iron), glass (silica sand, soda ash, limestone) and wallboard (gypsum) are all common in modern buildings.
- Granite is used to decorate the outsides of buildings as well as tiles for floors and counters. It is a hard stone that resists wear and weathering.
- Marble is used for interior walls and floors where there is less traffic (such as bathrooms) because it is soft.
Take a look at A Web Gallery of Stone Buildings and their Building Stone http://www.gly.uga.edu/railsback/BS-Main.html
ROADS & BRIDGES
A lot of crushed stone and concrete is used in the building of roads, highways, tunnels, bridges, airports and parking lots. This is often called our transportation infra-structure.