Colours from an ancient ocean

There are many sites around the Castlemaine area where 19th Century gold miners have removed all traces of soil in a process called ‘ground sluicing’. A blight upon the environment, but also, a wonderful opportunity to take a peek at the world beneath our feet.

These photos reveal one such pavement of thinly layered and intriguingly coloured mudstone. Apart from the colour, the most obvious feature in the photo is the parallel lines. The lines are the edges of thin layers of mud which were deposited on the seafloor millions of years ago (Photo 1). Most of the tiny layers appear to be very fine-grained mudstone, but some layers may be siltstone which is slightly coarser in grain-size.

But what causes the ochre like colours in the rock? We can see from the fine grain size of the rock and the thin layering that the mudstone was deposited on the seafloor at a time when bottom currents were gentle or even absent. This created an oxygen poor environment which was just right for the mineral pyrite (FeS2) to form in the muddy muck. After the mud turns to stone, and despite all the upheavals over the eons, pyrite remains in its pure state as tiny cubic crystals, that is, until erosion finally exposes the rock near the surface. When rock is exposed to within about 30 metres from the surface the oxygen-bearing groundwater reacts with the pyrite to form iron compounds that move through the weathered rock and start to fill cracks, or more porous parts of the weathered rock. These iron bearing minerals are called limonite or goethite – and these are the red-brown, or ochre coloured streaks (Photo 2).

Photo 1: The fine horizontal lines in this photo are the edges of dozens of thin layers of mud and silt that were laid down on the ocean floor. The dark brown fragments are pieces of limonite or goethite that have been weathered out of the outcrop and now just floating around.

Photo 2: The red-brown diagonal streak is probably a concentration of limonite formed along a tiny quartz vein.

This is the ninth  post in our geology series written by Clive Willman. 

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Another contribution to Fobif turns 25 show

Phil Ingamells has sent in the this photo and text for the Fobif turns 25 exhibition. New contributions from Janet Barker, Christine Henderson, Damian Kelly, and Philip and Judy Hopley, can be found here

Bluebell (Wahlenbergia stricta)

There are so many ways to see the natural world: as a complex web of interdependence; as a tough dog-eat-dog world of competitiveness; as a fragile, broken system now in need of rescue. All of these, and more, are valid views.

But for my pleasure, I can’t help seeing the natural world as something that outperforms the finest of our designers, architects, engineers and decorators. Evolution has produced a myriad of lifeforms that, at close scrutiny, startle us with their subtlety, their grandeur, their efficiency of design and their downright stunning beauty.

We can track the refinement of individual species through zillions of modifications over millennia, through the rough and tumble of survival, or we might see the trace of some guiding cosmic hand. Whatever remarkable path we might attribute nature’s evolution to, it has produced a glorious heritage, worthy of the utmost respect from us as individuals, from our land managers, and from those who govern us.

Its protection should be ‘core business’ for any responsible society, yet recent generations have put unprecedented pressure on what remains of that heritage. 

We too are a product of that journey, part of evolution’s family, but we are a long way from ensuring that the family will survive.

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More contributions to Fobif turns 25 show

Jeremy Holland and Jane Rusden have sent these photos and accompanying text for our Fobif turns 25 exhibition. There is is a few weeks to go if you would like to be part of this project. Check out the details here.

Jeremy Holland

Tarilta Creek

For me one of the most endearing features of our bush is its generally open nature.

This allows for relatively easy and enjoyable walking away from roads and tracks following natural features such as ridge-lines, spurs, creeks and gullies.

It is such a pleasure to be able to plan out a route and then proceed with it and thoroughly explore an area.

One of my favourite areas for this is around Tarilta Creek with its beautiful grassy flats interspersed with steep cliffs and interesting side gullies, sometimes with an occasional waterfall.

Jane Rusden

Crested Shrike-tits live along side us on our bush block, particularly in spring, they can be easily seen on a day basis which is a huge treat. The gully is full of Greybox and Whitebox, it’s a dry grassy woodland EVC. Often I hear them tearing bark as they search for an insect meal, which is how their presence is commonly discovered. I love their black crest, which looks like a Mohawk with a good dose of attitude. Their splash of vivid yellow is a welcome sight during cold grey days, which never fails to light my spirit.

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New Biodiversity Council

This news arrived last Tuesday and could be worth following to see how the huge environmental problems we all face can be successfully tackled …

Welcome to the first Biodiversity Council news!  

Biodiversity Council

The Australian Government’s response to Graeme Samuel’s 2020 review of our Federal environmental laws promises substantial advances. Minister Plibersek has announced an independent Federal Environmental Protection Agency, strong national standards including for forests (which are currently exempted from close scrutiny through Regional Forest Agreements), and regional planning to ensure …

Right now, Australia’s biodiversity is seeing catastrophic declines. This presents a major threat to all of us.

To make a difference, leading experts including Indigenous knowledge holders have united with philanthropists and 11 universities to form a new, independent council to bring forward the key issues facing our biodiversity and the solutions needed to halt its decline.

Our vision is that Australia’s biodiversity is recognised and valued nationally and globally as a priceless heritage, a foundation for our life and a defining feature of our country, and its future is recovered or secured.

Many solutions exist, and we can find others. But making these a reality requires working together.

So we’re working with communities, Traditional Owners, government, farmers and industries to solve Australia’s biodiversity crisis.

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Two more contributions for FOBIF show

Liz Martin and Max Schlachter have sent these photos and accompanying text for our Fobif turns 25 exhibition. There is is a few weeks to go if you would like to be part of this project. Check out the details here.

Liz Martin

Mt Alexander

I love to wander the ridges and gullies.

I often walk and find new places that I name. Valley of the dead trees is one. 

The different environments from the summit mist to the drier valleys are all worth exploring.

It is also a place for family walks and celebrations at the picnic ground or dog rocks. 

I love the misty days and the ancient rocks: the moss beds and the fascinating fungi.

It is also my refuge when life gets overwhelming and I wander the different areas with my camera, seeking out the leaves that have fallen,  lichen on the rocks and look forward to the fruiting of the mosses.

Max Schlachter

TRANSCRIPT

AUDIO INTERVIEW

CBA RADIO NATIONAL

2 FEBRUARY 2014

SUBJECT: Pink Mulla Mulla (Ptilotus exaltatus)

LOCATION: Baringhup West, Victoria

Host: Mulla Mulla, it’s such a beautiful name. Where does it come from?

Mulla Mulla: It’s a family name. Goes back for generations.

Host: I’ve also heard you called ‘exaltatus’. Sounds very grand!

Mulla Mulla: Well you wouldn’t know it now, but we used to be a very well-respected family in these parts. I don’t want to grease my own wheel or anything, but we were kind of a big deal.

Host: Oh right. And how do you feel about living on a roadside now?

Mulla Mulla: It’s tough for sure. I mean, we used to live all over these plains and now we’ve been pushed right out to the margins. We get rubbish thrown at us. It’s embarrassing actually. And the way things are going we won’t own any land at all in a few years. 

Host: That’s very sad, I’m sorry. Do you ever wish you were born a canola plant?

Mulla Mulla: Never! I’ll be damned if anyone is going to press me for cooking oil.

Host: Thanks very much for your time today Mulla Mulla.

Mulla Mulla: Any time Max. By the way, your car really needs a wash. 

ENDS

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FOBIF turns 25 show

Patrick Kavanagh’s contribution to the FOBIF turns 25 show. 

The first sound we heard when we first walked onto our place in 1994 was the haunting call of White-winged Choughs, Mooyin-unkil in Dja Dja Wurrung. They are such a presence in our bush at Strangways that we really imagine them as the landlords and landladies. They delight us constantly with their antics, especially when they are building their wonderful mud nests and come into our bird baths covered with mud from their labours.

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FOBIF turns 25

This is Bernard Slattery’s contribution to the FOBIF turns 25 show.

Disaster chic

Bushland reserves are often blocks of land left over after being thoroughly thrashed: having been exploited to the hilt, they’re rather flatteringly named ‘reserves’ and left to a kind of benign neglect. Battered though they are, some of them are amazing biodiversity reserves.

There are quite a few in this region, and I used to have a compulsion to cycle around the country checking them out. One of the most striking is the disused mine and quarry workings at the south end of Blanket Gully road: Guildford Bushland Reserve.

What can you say about this amazing place? It’s hard not to be horrified by the impression that some monster has torn through it in a fury, then left without a backward look. In a way this is true: the site seems to be a relic of times when miners weren’t obliged to rehabilitate their works.

On the other hand, there’s something mesmerising about the place: the colours, the extraordinary scars torn through the landscape, the heroic efforts of the vegetation to re-establish itself—all this tells a dramatic story, and, what’s more, a story which has a way to go.

And there’s a certain embarrassment in the site, as well. We may choose to be disapproving of past practices, but there’s a bit of truth in the aggressive bumper sticker proclaiming that ‘everything you own, wear, use, and eat has been cut down or dug up from the ground’. This site is challenge: ‘you don’t like it? Well, do better.’

As explained in a previous post all contributions to the FOBIF turns 25 exhibition are welcome and will be posted on this site. A selection will be chosen for display in at the Arts Hub, which will run between 25 February to 13 March 2023. You can see the current contributions here.

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Fuel breaks: the story so far

Local enviro groups have been briefed on the progress of Strategic Fuel Breaks in the region. As with most things to do with fire and biodiversity management, the picture so far is patchy and its final effects hard to assess.

On the one hand, the quality of DELWP consultation on the project has been unusually good, and every attempt seems to have been made to adjust works to local conditions.

On the other, we have to face the fact that, like every state wide project, this one has a kind of juggernaut effect: lines have been drawn on maps, and local adjustments to these lines—if any adjustments are possible—are going to have to be hard fought.

FOBIF’s immediate concerns include the following:

  • The fuel breaks proposed for the Fryers Ridge and Porcupine Ridge. We have been told that works in these areas will not be started for at least 12 months, but the prospect of their going ahead at all brings no joy to anyone interested in local biodiversity. Although we are fully aware of the importance of firefighter access and safety in these areas, we’re not convinced that it’s best achieved by mowing down the bush. FOBIF has suggested alternatives to slashing and mulching in sensitive areas: these seem to have gone nowhere
  • Monitoring: We believe that baseline monitoring of Break sites, and ongoing monitoring of works, are essential. Recent discussions suggest that these will not be as rigorously implemented as we’d like. We’re not sure if these works are governed by the transparency requirements of the Code of Practice for Bushfire Management. They should be…but on the other hand, the Code is not always followed.
  • Methods: Experimental use of brushcutters to manage vegetation along Bells Lane track in the Muckleford forest suggests that this method is as effective as tractor mounted machinery, and less damaging in terms of soil disturbance and weed growth. We’re interested in seeing it as the preferred method.

FOBIF has repeatedly made it clear we are not opposed to fire breaks close to settlements. As to more remote forested areas, we still have concerns on a number of levels, mainly to do with the thorny problem of reconciling safety and biodiversity concerns. Are these two objectives irreconcilable? We are occasionally invited to believe so  by  hard heads in land management, and it’s sobering to read in IGEM’s report into the 2019-20 fire season the suggestion that people should be prepared to ‘create safety by navigating complex trade-offs between irreconcilable goals.’ The same report, however, suggests that greater resourcing for land management might get better results all round. We’d agree with that.

We’ve been informed that this region has been a bit of a pilot project for fuel breaks, and that future works may not be as rigorously considered and implemented as they have so far in this area. That’s a very disturbing thought. We’ll see. We believe that any hope of getting a half way decent result on the ‘irreconcilable goals’ requires more, not less, attention to detail.

In the meantime, we hope that consultations on these and other matters can continue.

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What do we know, and where does it lead us?

On the subject of monitoring (see above), how do you decide whether to continue with a project you’ve been working on?

Well, you probably check to see how successful you’ve been with your approach so far. On this, we offer the following two apparently contradictory findings of the report on the 2020 fire season by the Inspector General for Emergency Management (IGEM):

Finding 4.19 Forest Fire Management Victoria has established a strong foundation of monitoring, evaluation and research that has resulted in regular reporting against clear objectives.

Finding 4.21 The effectiveness of Victoria’s fuel management program cannot be comprehensively measured due to a lack of measurable objectives adopted by all land and fire agencies, gaps in the current tools and models used, and a lack of capacity and capability to support the requirements of this work across the sector.’

How do these two findings, which are printed on the same page, sit together? We’re not sure.

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Oh no–another menace

Not wanting to be depressing or anything as the ‘festive season’ approaches, but here’s the Department of Agriculture on a potentially serious local menace:

‘Chilean needle grass is becoming a serious pasture and environmental weed in south-eastern Australia. It is very invasive and forms dense stands in pastures, bushland and roadsides.

‘It tolerates drought and heavy grazing, giving it great potential to spread and over-run existing vegetation. The potential distribution of Chilean needle grass in Australia is estimated to exceed 40 million hectares.’

On a more constructive note, have a look at the sheet below, produced by Margaret Panter to help landowners identify and respond to the needlegrass menace (click on it to see it full size):

Click to see full size.

 

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