The suburb of Beverley is underlain with layers of clays and sandy clays suitable for kiln fired bricks. In colonial times the Beverley clays were described as incomparable for the production of red bricks.
Clay deposits were laid down over past five million years as material deposited by variable flows of the River Torrens. The clay deposits represent alluvial material washed onto the Adelaide plains by erosion and weathering of minerals in the Mount Lofty Ranges. The scientific name for the material is Hindmash Clay. From the early days of settlement brickmakers utilised the alluvial clays of the Torrens floodplain.
Good quality brick clays consist predominantly of the clay minerals kaolinite and illite. The quality of these minerals impart desirable properties which are important in forming and firing a brick. Quantity and particle size of the silica sand component of the pug material is also critical to forming and firing behaviour. Red brick colours are due to the presence of iron minerals in the clay.
Solomon Williams and William Willis bricks began operations in 1876 in Beverley. James brickworks began operations in 1910 at Welland. Hallett bricks were established at adjoining Allenby Gardens in 1912. For a while after 1945 there were nine brickworks in the Beverley area.
James Brickworks ceased production in the early 1970s due to the depletion of the clay reserves and the introduction of pollution controls. The James Brickworks site is now a museum to Beverley’s brick industry.
Clay deposits were mined for over 100 years. The hole created by clay mining is known locally as a "pug hole". The clay is called pug, and the action of mixing clay with sand is pugging. The clay mining created enormous pug holes that have since been rehabilitated. There is no surface features remaining of the pug holes shown in the image.
From the mid-1960s to 1990 the depleted clay quarry pits were back filled with with waste material, sand and soil. Some of the pug holes were active rubbish tips. As well as household rubbish, a variety of industrial materials, including radioactive materials, hazardous mineral waste, paints, oils and solvents were disposed in the pug holes. All of the pug holes are now filled and covered with soil. Most of the rehabilitated areas are now built over. The extensive grass area next to The Dome stadium is the largest open area in the suburb covering a pug hole location.
Visit the listed coordinates and nearby waypoints, and make your observations. You will need to answer the following eathscience questions. Please provide your answers to the cache owner in a timely manner, i.e. less than a fortnight.
-Describe the remediated pug hole at the listed coordinates. Texture, flatness?
-Compare with the original ground surface at the waypoint coordinates. Texture, flatness?
-Can you see any evidence of brick making near the waypoint coordinates?
-Grab a handfull of material from the clay deposit. How does it feel?
-Is the material predominately sandy or clay? Wet your grab sample. What happens to the material?