The previous post introduced the rock line-up located beside the gravel road that leads to a boat ramp located east of New Norfolk. Resting impressively nearby, the massive stump pictured below was labelled as a Swamp Gum/Mountain Ash/Eucalyptus Regnans – the world’s tallest flowering tree.
This Eucalyptus Regnans tree began life when Queen Elizabeth 1st was on the throne in England in the 16th century.
The tree stump was collected from west of New Norfolk after growing to 90 metres tall and 3 metres wide, before being felled by a bush fire. Nevertheless, the remains of this grand old-growth forest gum tree reminds me of the wonderful original forest trees we have lost to pulp and paper making in Tasmania and how important it is to protect what we have left.
The placement of this 30 tonne tree stump by Australian Newsprint Mills in association with the New Norfolk Council was made as part of the Australian Bicentennial year of celebrations of European settlement in 1988.
The vegetation beside the gravel road was a lush, overgrown, infestation of blackberry bushes. The photo below shows the steam effluent of the Norske Skog newsprint production mill in the distance.
After the rocks and tree stump diversion, I stepped back onto the gravel road where I could see the Derwent River and some building structures at the bottom of the incline.
On Stage 14 , I reached the turn off from the Lyell Highway around 12.45 pm and stopped to read my maps in order to be certain that I would find an alternative trail situated closer to the edge of the Derwent River than the highway. From this boat ramp road (has a sign with boat ramp symbol on the highway), the trail looked definite and continuous so I peeled off from the Highway.
A few metres along the gravel road, a ‘parkland’ to the left of the road was covered with the gentle leaf droppings of the surrounding gum trees. In the dappled light, I noticed a row of large rocks standing to attention neatly, each with a name tag.
A few metres from the rock row, a sign provided additional information. It seems the sign was placed here in 1988 as part of the Australian Bicentennial year of celebrations of European settlement. Who by and why is not clear.
Were these rocks and the sign a help in understanding the local geology? Yes and no. Mostly the information on the sign referred to locations further west and north of New Norfolk, the town which is located a few kilometres west of this display. I did learn that, about the time when Tasmania was beginning to separate from mainland Australia 60 million years ago, the Derwent River began to form; a young river by the standards of some of the rivers of the world (the Rhine River began to form 240 million years ago, the Colorado River started forming about 75 million years ago, and the Nile about 70 million years ago).
Why was this location chosen to present this display? Who, apart from the occasional walker like me, would find and examine this display? People travelling in vehicles would not be stopping to look. Rather they would be focussed on reaching the river edge ramp to launch their boats. Very strange.
Patricia Roberts-Thompson (http://taroona.tas.au/assets/document/1354363720-a_walk_along_alum_cliffs.pdf) indicates that the first recorded reference to the Alum Cliffs was in 1847. She explains that these rocks, Permian mudstone (250 million years old, contain iron pyrites and, as the rock weathers, the pyrite oxidises and produces sulphuric acid which reacts with the limey clay to produce alum. Roberts-Thompson could find no evidence that the alum has been extracted from our cliffs for commercial purposes.
Simon Stephen’s research (http://taroona.tas.au/assets/document/1352547986-geology_reduced.pdf) is in sync with that of Patricia Roberts-Thompson when he says the mudstone on the Alum Cliffs contains much sulphur so that when struck a strong smell is emitted. “Much of the sulphur manifests itself as a white encrustation on thee sheltered areas of the cliffs. It has a distinct bitter taste…” (Trust me – I won’t be taking a bite or licking it). Stephen’s article is exceptionally interesting not the least because it pin points a geological fault line which is near Crayfish Point (where I have already walked) and which extends out through the end of Hinsby Beach and then under the water along the Alum Cliffs. I don’t know if any seismological activity has occurred in my life time there nor whether any is expected. I’d rather nothing happened during my forthcoming Stage 12 walk along the Alum Cliffs.
The Kingborough Council distributes a brochure with the following information: “The route followed by today’s Alum Cliffs Track has long been a coastal path used by local people. In 1988 it was formally developed as part of Australia’s Bicentennial celebrations. In more recent years, Council has upgraded the southern section of the track, which climbs from Tyndall Beach through coastal blue gum forest with tall silver banksias. The track then winds up through silver peppermint bushland, dips into a glorious fern filled gully, before rising again onto headlands for commanding views over Storm Bay and the Derwent Estuary. A new start to the track without steps has now been constructed above Tyndall Beach to make the track accessible to more users. The Alum Cliffs are so named because alum – a compound used in dyeing, tanning and medicinal products – is found in the cliffs.”
It is a shame that all instructions to reach and walk the Alum Cliffs use Kingston Beach in the south as the base to walk north and then return. Websites provide information about multiple entrances along the route at Tyndall Rd, Harpers Rd, Taronga Rd. Apparently a Metro bus stop is located 100m south of the intersection of Taronga Rd and Channel Highway. I wonder how many people have walked the Alum Cliffs Track from the northern end and, if not, like me would like to read advice about how to tackle the cliffs departing from Hinsby Beach.
It may be that, on Stage 12, I will start out at the end of the Hinsby Beach and then be forced to retrace my steps, return to the Channel Highway and walk up the winding fairly narrow Highway with no pedestrian walkway until I reach the Brickfields Track. From http://www.greaterhobarttrails.com.au/track/brickfields-track I understand that “the Brickfields Track links between Taronga Rd (adjacent to the Channel Highway) in Bonnet Hill and links to the Alum Cliffs Track. The route of the Brickfields Track takes you through the historic remains of the brick-making area; part of the nearby and short lived 1840’s convict probation station. The track is a mix of narrow bush track and timber boardwalk with some steps along the route.”