A Little History
The site you are visiting was once a brickworks factory in 1891. At this time the Depression caused many brickworks to close, however, the Wallsend Brickworks did not follow the trend and operated for 86 years.. It closed in 1977. The Council earmarked the site for landfill in 1980 but this didn’t eventuate and in 1986 the area was declared as open space. In 1999 the members of Wallsend East Residents Association encouraged the Council to develop the site as a park. The council started to develop the park in 2002 and it was officially opened on the 9th April 2006.
The artworks in the park have been entirely made from recycled bricks, including some of the original Wallsend Bricks. Now follow the path west till it takes you past the sculpture 'Kullas Incubator' by Tim Spellman. The three pieces represent the now demolished buildings of the brickworks – the arches represent the kilns and the hemisphere enclosed within the arches represent the bricks.
If you would like to know more about the history of this site check out S 32° 54.426 E 151° 41.085
Geology
Head to S 32° 54.468 E 151° 41.177. You will find an information panel.
The Wallsend brickmakers used every rock types you can see in the pit wall. After breaking up the rock by blasting, they crushed, ground and mixed it with water to give about a 10% moisture content. Clay and shale were mixed with equal or lesser quantities of sandstone. The high clay mineral content of the sandstone here is what made it suitable for brickmaking. The Wallsend Brick Co. Specialised in red and brown bricks. The sedimentary rocks on site contain small amounts of iron, when the bricks were fired under oxidising conditions they gave a lovely red colour. The Wallsend Brick Co. Also manufactured white and cream coloured bricks using the grey shale extracted from a pit near Merewether Heights.
Looking east you will see the pit face. The rock layers in the pit face once extended over the spot where you now stand. Look at the rock face of the brickpit and you are looking back 250 million years, before the time of dinosaurs, birds and flowering plants. At this time Australia was joined to Antarctica, and eastern Australia lay close to the South Pole. Ancient rivers, floodplain lakes and forest swamps covered the Newcastle area, depositing sand, mud and peat as sediment. These sediments now form the rock layers of sandstone, shale and coal that you can see in the pit face.
The climate was cool and wet. During autumn, before the long dark winters, the trees of the Glossopteris flora dropped their leaves. These leaves were washed into lakes and covered with mud. After burial, heating and compaction converted the mud into the grey shale and the leaves into black, carbonised fossils. Many forests grew in large fresh water swamps, forming peat, which was later deeply buried to produce coal.
Reconstruction of a Glossopteris plant: a) A Glossopteris tree; b) the pollen producing organ (Eretmonia); c) a seed-bearing organ attached to a Glossopteris leaf; d-g) examples of different types of Glossopteris fructification.
The rock face marks the limit of excavation. Atmospheric gases, sunlight and rain water have changed the surfaces of the exposed rocks to crumbly clay and sand, opened up natural cracks and stained them with orange iron oxides. Rock faces showing the most weathering have been exposed to the elements the longest. Can you pick the oldest face?
Find a log fossil - Large blocks of light grey sandstone have been used for landscaping around the park. They come from the thick sandstone layer making up the lower part of the pit face. Some blocks contain brown fossils of wood such as bark from a tree. The sandstone also contains black leaf and other fossil plant fragments.
Look at the diagram on the far right panel. It identifies the layers in the face by rock type and by the origin of the sediments that formed it.
Now we are going to introduce you to the Stratigraphic Column, something geologists find very very useful!
What is a stratigraphic column I hear you ask? Well, a stratigraphic column is a representation used in geology to describe the vertical location of rock units in a particular area. A typical stratigraphic column shows a sequence of rocks, with the oldest rocks on the bottom and the youngest on top. It is a very useful tool to understand the depositional sequence of an area.
To log your find you are required to fill in the blank lithologies (rock types) from 1 through to 10 on the following stratigraphic column by looking at the cutting. The above photo gives you a general summary of the lithology but you will have to work out the rest. You can email us just your answers, you don't have to fill in the sheet and then email us - unless you really want to. There is a sign near one of the WP to help you if you get stuck!:
Reference
Kerr, R. 2005. Geology and Brickmaking, Interpretation Report.