The Quarry And the Brick Making Process

Before the Company started to mine, there was no valley where the brickworks is now, just a flat peice of land sloping towards the Don Valley River.

Here, we can see the evolution of the Quarry at the Brickworks.

The method used to extract the materials needed to make brick was Open Pit Mining. Open-pit mines are used when deposits of commercially useful minerals or rock are found near the surface. Mining is most associated with underground mining, witch is used when the materials needed are found deep within the earth and hard to reach. In this situation, open pit extraction was more cost effective.
For Example, here is an open pit Diamond Mine.

Here You can see the materials needed are close to the surface.