By Belinda Hirst | Posted: Friday October 1, 2021
Every year Aggregates & Quarry Association run a Nationwide competition called Rock Our Future. Students are encouraged to visit a local quarry and write an essay of no more than 500 words describing their experience at the quarry and what they learned during the visit. After a number of excellent entries, the winner of the Year 8 section was Olivia Morris from Room 4, OIS. This is her award-winning entry.
Under The Hills
In Oamaru, there is a very special quarry business like no other. The Parkside Quarry specialises in limestone, or Oamaru stone.
The land the Parkside Quarry is sitting on was purchased in 1874, the proud owners the first generation of the Parkside Quarry family, seven generations ago. They had no idea what was beneath those rolling hills, until they dug deep, and discovered underneath that scenic view was a lot of limestone.
Our local geologist, Sasha Morriss taught us that limestone forms underwater, and the limestone in this particular quarry formed around 25-35 million years ago. Back then, all the way up to Lake Aviemore, Oamaru was under the sea. Limestone is made up of millions of tiny little shells and fossils that built up on the seafloor.
In the 1930’s a man named Bill Taylor used dynamite to break down limestone outcrops. Now limestone blocks are being cut out with the help of hydraulic circular saws fitted onto tractor arms, and wires are pegged along the ground so the saws are cutting as accurately as possible. This is a lot safer for the workers. Around 500-600 two ton limestone blocks are quarried out of the hills per day!
Circular saws pulled along metal bars cut the blocks to precisely the right size with precisely the right look.
When the quarry first started up, there were 50-60 people employed in the industry. Now, due to machines evolving, there are currently only 15 workers at the quarry. One of these helpful new machines is ZEDA, a huge robotic frame with many saw attachments that can carve tiny little details into blocks of limestone. O.I.S’s writing group had the pleasure to meet her, and she was one of my favourite things to see. You programme the shape you want and the measurements into a computer, and she will make it. Some of her masterpieces include a life-size seal, a bust of Gollum, and perfect spheres of limestone. ZEDA is definitely an improvement to the Parkside Quarry industry, providing the hand-made look in a statue, a clean track record of work attendance, and a new angle to the business.
The Parkside Quarry business also sells lime dust, ground up limestone. The aforementioned Bill Taylor set up this industry. The limestone dust is really good as a fertiliser, and is great for chickens to eat. To make sure the limestone dust is the best quality possible, it goes through a sort of elevator, gets cooked and dried and crushed repeatedly so it gets finer. Parkside Quarry uses coal to run this machinery, a problem they are not sure how to address. A more sustainable fuel would be ideal for the company’s otherwise eco-friendly way of business.
Parkside Quarry is an awesome place to visit, with great history, and chances to learn more around every corner. If you ever get the chance to visit, I strongly recommend it!