Our Natural History
TO learn about the Scenic Rim’s incredible natural history read on.
The Scenic Rim is home to six National Parks. In December 1994 parts of the Main Range, Lamington, Springbrook and Mt Barney National Parks were included in the Central Eastern Rainforest Reserves Australian World Heritage Listed Area. To find out more about all of our National Parks click here.
IT’S not until you investigate how the Scenic Rim came to be that you realise how significant this dense cluster of mountains is. The Scenic Rim Mountains and the Mt Warning area in northern NSW are known as the Green Cauldron and were once a volcanic hotspot, which over the years has grown into a lush landscape featuring six World Heritage listed National Parks.
Scenic Rim geologist, Dr John Jackson, says the Scenic Rim was formed over a three million year period, about 26 million years ago. To explain the phenomenon which led to the creation of such a dense build-up of mountains, John likens Australia to a frying pan on a gas stove.
Pan on hot stove
“As you move across the gas stove the heat changes depending on where you are,” he says.
“As the heat intensified, volcanic activity erupted and the mountains formed from magmas and lavas that intruded from the hotspot. Mt Warning and Focal Point Mountains are known volcanoes and John says there were most probably others, but proving it is difficult.
“Australia was travelling north over a hotspot, then it changed direction and slowed down and that is the real reason for the Scenic Rim,” he says.
“The change in direction and the slower speed allowed for the build up of the dense mountain range.
“To give you an idea of the speeds, when Peak Crossing to the Glass House Mountains was formed we were travelling about 70km/million years. That speed slowed to 26km/million years when the Scenic Rim was created and you get the effect of the mountains that are all stacked up together.
“By the time we reached Mt Warning, Australia speeds up again and the mountains are more dispersed.”
Flora and Fauna
This volcanic activity not only led to the creation of our mountain range, but it has enabled the growth of the Scenic Rim’s rich flora and fauna. When combined with our temperate climate, the region’s rich basalt soils have proven fertile grounds for rainforests to prosper.
“It all comes down to the chemistry of the rocks and the soil which leads to different vegetation and different birds and animals which feed on the different seeds.
“All of this comes from the rocks, that’s where it all begins.”
To read more about the Scenic Rim’s rock layers, click here.
The Scenic Rim region is a real treasure trove of unique plants, animals and distinctive vegetation types. The mountains preserve living links to Australia’s ancient past, while one of Australia’s two species of lyrebird inhabits the region’s rainforest and wet eucalypt forests. The stories, rituals and traditions of the indigenous inhabitants are woven around the natural environment and highlight their connection to a living landscape.
The varied landscape and natural beauty of the Scenic Rim made an indelible impression on the early settlers such as Logan, Cunningham and Fraser, who all commented on the beauty of the area.
The Scenic Rim has long attracted naturalists, scientists, artists and bushwalkers who are interested in studying and enjoying the area’s rich natural history. The region has had some fierce defenders of its natural heritage, Arthur Groom, Romeo Lahey and Judith Wright among the three most influential, so it is fitting that Queensland’s first National Park was declared here in 1908.
The region’s volcanic past has left a rich legacy, some of the most fertile soils in south-east Queensland. The Kalbar, Boonah and Aratula regions, as well as Mt Tamborine, boast fertile alluvial soils, rich in nutrients which ensure plant growth. Subsequently these areas continue to be home to viable agricultural activity, including horticultural, beef and grain production.
As you move through the region you’ll notice a change in the vegetation. In Binna Burra and at O’Reillys see high altitude beech forests, including the moss-covered gnarled trunks of the Antarctic Beech.
Mt Tamborine and Binna Burra are home to sub-tropical rainforests. Dense dry vine rainforest scrub, with its tangled vines, can be found in the Mt Barney mountain area and in parts of the Mt Chinghee region.
Brigalow softwood scrub is found at Kalbar, while mountain Eucalypt forests are found in the higher rainfall areas of Spicer’s Gap and Mt Tamborine.
You’ll see heath and orchids such as the Pink Rock Orchid and the King Orchid on the rocky outcrops of Mt French and Mt Greville.
Wyaralong and Kooralbyn are home to sandstone ridges forest, while the Logan Valley, Bremer and parts of Wyaralong are dominated by Blue Gum fringing forests.
A Short Geohistory of the Green Cauldron
By John Jackson, Boonah’s Rock Doctor
IN north-eastern New South Wales and south-eastern Queensland there exists a unique collection of landscapes that contain a fascinating geological history. These landscapes include The Scenic Rim in Queensland and the Mount Warning area in New South Wales. Collectively these distinctive landscapes are called The Green Cauldron and include six World Heritage listed National Parks.
The Green Cauldron landscapes are like huge amphitheatres. The Basement rocks (see blue shading) beneath the Green Cauldron act like rooms below that store future action. The Floor Rocks (see green shading) are like a stage where major dramas will be played out. Finally, there are the tall rocks that appear as if they are walls around and they are called the Rim Rocks (indicated in orange).
The oldest rocks (400 to 210 million years old) are the Basement Rocks. These are rocks made of marine sediments that have been deformed and intruded by hot, slow-cooling, sticky magma which is a hot liquid rock. The Basement Rocks can be seen Mt Tamborine to the Gold Coast. They can also be seen in the foothills of Mt Barney.
Above them are the Floor Rocks (210 to 65 million years old). These have been eroded from the Basement Rocks and contain pebbles, gravel, sand, silt and clay. Such sediments were deposited by freshwater streams, rivers and lakes. The younger deposits also contain peat that was later converted to coal. The floor rocks are evident in road cuts from Canungra, through Beaudesert to Boonah.
The third and final group of rocks (24 million to 20 million years old) that make up the landscapes of the Green Cauldron are called the Rim Rocks. These rocks are made from a range of magmas and lavas that intruded the Australian Continent from a hot spot in the earth’s mantle (mantle plume). The Rim Rocks can be seen from Cunningham’s Gap on the Main Range, through Mount Barney and onto Mount Warning.
The Rim Rocks have crystallised from hot, liquid magma. There are intrusive sills such as Mount French, runny lava flows like the Main Range, collapsed cauldrons like Mount Alford, magma chambers such as Mount Barney, shield volcanoes as the one found at Mt Warning and lava columns seen at Fingal Head.