“Sod the wine, I want to suck on the writing. This man White is an instinctive writer, bloody rare to find one who actually pulls it off, as in still gets a meaning across with concision. Sharp arbitrage of speed and risk, closest thing I can think of to Cicero’s ‘motus continuum animi.’

Probably takes a drink or two to connect like that: he literally paints his senses on the page.”

DBC Pierre (Vernon God Little, Ludmila’s Broken English, Lights Out In Wonderland)

Winner: Booker prize; Whitbread prize; Bollinger Wodehouse Everyman prize; James Joyce Award from the Literary & Historical Society of University College Dublin

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10 August 2010

MAP OF THE GEOLOGY OF McLAREN VALE






COONAWARRA HAS NO COPYRIGHT ON LIMESTONE: EOCENE BLANCHE POINT AND TORTACHILLA LIMESTONE IN THE TUNNEL BELOW MAXWELL WINES

Leon Bignell's Speech  
The House Of Assembly
South Australian Parliament

by LEON BIGNELL, MEMBER FOR MAWSON, 21 July 2010


Mr BIGNELL (Mawson) (15:30): I rise today to inform the house of a new map that was released last week. It is a geological map that shows the different rock formations in the McLaren Vale region. Some of those rocks date back 1.6 billion years. It is very important for a winegrowing region to understand what is below the soil. In fact, there is a huge impact on wine, depending on what sort of rocks it is grown upon.

I would really like to congratulate Philip White, the wine critic, Jeffrey Olliver, PIRSA's geologist Wolfgang Priess and William Fairburn who, 35 years ago, when they were working together here in Adelaide and all very much interested in geology, came up with the idea of mapping South Australia's wine regions, their geological formations and their importance. It took a while and there were several years of no activity at all but, for these four guys, their dream became a reality last week. I would also like to thank PIRSA for its contribution in helping make this map a possibility.

There were more than 140 people at the Bocce Club at McLaren Vale for the launch of the map last week, showing just how important it is to the region. There are seven distinct terrains in the McLaren Vale wine region and, as I said, each of those has a very important impact on the taste of the wine, which is why people may have seen Philip White getting around in vineyards over recent years, licking rocks. It always looks a little strange, but he says that what you taste in the wine is what you taste in the rocks, and I will take Whitey's word for that.


REFLECTED IN WHITEY'S SHADES IS THE INTERFACE WHERE THE NEOPROTEROZOIC BEDROCK UNDELIES THE NORTH MASLIN SANDS AT THE CUTTING NEAR CHAPEL HILL: 700 MILLION YEARS OF GEOLOGY MISSING! photo KATE ELMES

Ms Bedford interjecting:

Mr BIGNELL: He is very dedicated, and he is also a very avid reader of Hansard, and I am sure that he will be reading this note of congratulation. We have also had another big week. I have come in here many times to talk about what a wonderful region McLaren Vale is. Two nights ago in Melbourne at the National Produce Awards, McLaren Vale was named by Delicious magazine the best region in Australia. This is what the judges had to say:

"With its mix of outstanding wineries and restaurants, great produce and a stunning coastline, South Australia's McLaren Vale was the natural choice as this year's winner. Being a wine region by the sea is definitely an advantage. The chefs here at places like Fino, Salopian Inn and Russell's really know how to make the most of the produce and seafood, and the Willunga Farmers Market is a highlight. There's a great synergy. It's one of the most active regions in the country for permaculture, and you see it at the market."

PARLIAMENTARY MEMBER FOR THE SEAT OF MAWSON, LEON BIGNELL, HELPING OUT IN DUDLEY BROWN'S INKWELL VINEYARD

Coming to the world of wine from deep beneath the flavoured ground

by PHILIP WHITE

When I was a kid, I lived in Kanmantoo, a copper mining town on the east side of the South Mount Lofty Ranges in South Australia. I earned my pocket money working as a field assistant to various geologists and surveyors as they explored, drilled and mapped our region, searching for an el dorado.

After years of handling, cataloguing, archiving and assaying hard rock surface samples and drill cores, at a very young age I had developed a deep respect and basic understanding of the ancient tortured geology of my region.

I also developed a profound reverence for the science and practitioners of geology, quickly appreciating two of their quirks. The first was that geologists commonly taste rocks to help identify their nature. Depending on their composition, rocks have different flavours. Geologists lick rocks.

The second was that these remarkable people think in three dimensions. They learn to read the rock, and understand its intricate folds, rolls and layers deep beneath the Earth’s surface.


Once the great conical pit was dug at Kanmantoo (above), and one could stand in its depths, gazing over the mess of metamorphised hard rock in the faces reaching up for over two hundred metres to the surface, it was immediately obvious how thin and fickle the soil was.

Over all those three dimensional folds and curls of mighty rock, that epidermis of soil way above looked so frail, and inconsequential, and two-dimensional. Relatively, it had no depth.

MY BROTHER STEPHEN, ONE OF THE MINERS WHO DUG THE KANMANTOO PIT, IS STILL A HARDROCK UNDERGROUND MINER IN WESTERN AUSTRALIA

It made me shiver to wonder what sustenance had fed the world famous Kanmantoo St George's Vineyard during its blaze of fame from the beginning of the colony to the Depression. Like what on Earth - or in Earth - had lent this Adelaide Hills wine such flavour that it won the gold medal for best red wine in the world at the Paris Exposition Universelle of 1889, celebrating the centenary of the French Revolution and the opening of the Eiffel Tower?

The secret is unfolding still. Many years later, whilst working on the McLaren Vale map, the formidable geologist, Wolfgang Priess, reinforced my suspicion about the thin frailty of soil when he murmured “Some geologists think soil is the dandruff of the Earth.”

We had been discussing my frustration with viticulturers and winemakers, and their obsession with dirt, rather than geology. Soil, I was joking, was only two-dimensional compared to geology, which had depth, and flavour.

DIAMOND DRILL BITS FOR DRILLING CORE SAMPLES FROM DEEP IN THE EARTH - SEE BELOW

I had worked on the same office floor as Wolf, back in the ’seventies, when I was lucky to be part of the Geological Survey Division of the South Australian Department of Mines and Energy. This was a time when this new thing called “the environment” was only just being discovered. South Australia had a visionary Premier, Don Dunstan, whose regime oversaw the beginnings of progressive environment management and a slow-down in actual mining, but an incredible acceleration and intensification of exploration and mapping. That Department had a great fleet of drilling rigs, probably the biggest assembled in Australia 'til then, and it had a higher percentage of scientists with doctorates and significant academic qualifications than any other.

The frisson of creativity and discovery there was exciting, addictive and hugely rewarding: nearly four decades later, ore bodies discovered during that intensive exploratory surge are still being exposed and mined. The Olympic Dam deposit on Roxby Downs is a good example.

They certainly fed me and my crew with plenty of drill cores and rock samples for cataloguing, sampling, boxing and storage in the new Core Library at Glenside. We had thousands of kilometres of drill core samples there for immediate retrieval, examination and further analysis. This was the best facility of its type on Earth, where we built one of South Australia's first computer databases, using COBOL and a skrillion punch cards. Maire Mannik (below) was the brilliant pioneering programmer.

Elsewhere on that busy head office floor worked Jeff Olliver, who was head of the non-metallic minerals section. And twenty feet from me was W. A. “Bill” Fairburn, the fastidious boffin who edited the constant flow of academic papers the Survey produced. I learned an astonishing amount, listening to years of Bill’s tenacious questioning of the authors of those papers. Those bright discussions covered every strange backwater of the vast realm of geological science.

Geologists are thirsty folk. Interminable swathes of time spent nose down in the desert builds up significant reserves of thirst, which take mighty city lunches to assuage, nose to the winestone. Supervisor of many of these was my boss, the legendary Bob Wildy. Red wine, and much of it, was compulsory. The regular comparison and discussion of wines from the various South Australian viticulture regions led invariably to posturings on their relative geology. But not very deeply.

Eventually, after a study tour of the geologies of the wine regions of France, Bill Fairburn came back and addressed the Geological Survey, suggesting that a formal attempt be made to properly map the wine regions.

Bill’s address was rather humourously regarded: when there was gold and uranium to be found, his suggestion seemed frivolous. No funding was provided. But last month, thirty two years after that meeting, the first map was published.

Soon after Bill’s speech, I had largely abandoned rocks and went off to pursue my freelance writing career in television, film and papers. But those epochs of geological thirst led quickly to the world of wine writing, which increasingly became the focus of my hopeless attempts at earning a living.

A Michael Dransfield poem from 1972 had first led to me consider the relationship between wine and country, and the writing it could unleash. “Taste it. Not bitter,” Michael wrote of an old Hunter Shiraz in Wine Tasting, “but with the dust of the outback prominent.” A decade later, I was in the Hunter Valley being lectured by that almighty rogue, Murray Tyrrell.

“Our reds start out like young Bordeaux,” he boasted to a group of tourists, “and they end up like beyoootiful Burgundies.” And then, staring at me, “and you can smell the brown coal coming up through them from the ground beneath.”

I had already formed a strong belief that any coal/bitumen/peat/lignite characters possessed by the wines of the Hunter reflected the hydrogen sulphide in the air above, an exudate of the filthy local coal mining industry, rather than a product of the deep alluvial geology covering its coal strata. Any other H2S I suspected came from McLaren Vale, which shipped enormous volumes of its bulk wine into the Hunter for consequent blending, disguising and packaging as Hunter wine. Vales wines were stacked with sulphide from bad winemaking in those days. The Hunter vignerons had rather politely changed its common name from “rotten egg gas” to “sweaty saddle”, giving rise to evocative images of bushrangers, horse rustlers, and cattle thieves, all stereotypes fully understood by the Tyrrells.

Peaty Vales aromas, however, were another puzzle; one which took me a further 28 years to solve.

Pardon this meandering.

THE FREAKY TERAZZO-LIKE GEOLOGY OF THE TALUS SLOPE AT MARIUS WINES ON THE WILLUNGA FAULTLINE, McLAREN VALE. THIS ROCK, FROM VARIOUS 600 MILLION YEAR PLUS SOURCES IN AN ANCIENT MOUNTAIN RANGE, HAS BEEN BROKEN AND MIXED AND WORKED AND REWORKED BY GLACIAL ACTIONS AND EXTREME RIVERINE ENERGY AND THEN KER-SPLOSHED INTO ITS CURRENT LOCATION IN THE KURRAJONG FORMATION.

Very early in my winewriting career, I began to taste the rocks and dirt of the many vineyards I visited. The viticulturer’s reaction was always disbelief and horror. To me, the disbelieving reaction was preferred. Horror usually indicated a farmer who’d sprayed so much poison on his ground that he thought I must surely die from ingesting his poisons. There are plenty of those extant, unfortunately. Monstano's Roundup comes to mind. And I still encounter winemakers and grapegrowers who surprise me by doubting that the water-soluble mineral flavourants in their soil could possibly influence the flavour of the water that their vine roots drink, and squeeze up and out into their berries.

Bill Fairburn corresponded with me irregularly during my twenty years writing wine on The Advertiser, the local metropolitan and state daily. He would enjoy setting me right when my geological posturing went awry, was always helpful when I encountered strange geologies on my endless vineyard treks, and often vented his frustration that he couldn’t get support from any winemakers for his map-making efforts. He would spend weekends and holidays in the field with his geological pick and notepad, mapping geology. McLaren Vale, and then the Barossa.

Botched, hurried versions of his work made it onto two government pamphlets in 2000. The lack of interest from the winemakers of both regions was deplorable. The owner of one trendy Barossa old-vine boutique whose vines Bill recognized to be dying of salinity from stupid irrigation regimes hissed “who gives a fuck about geology”, and sent him packing.

So Bill did pack. Packed right up and went back to Yorkshire to retire.

In 2008 I moved from Kanmantoo to McLaren Vale, where I discovered Jeff Olliver was living, growing grapes, and working as a consulting geologist. We immediately decided to pursue Bill’s work, and renew contact with him. This coincided with Dudley Brown, new chairman of the McLaren Vale Grape Wine And Tourism Association, visiting me to discuss the need for a map of the McLaren Vale Wine Region.

JEFF OLLIVER CUDDLES A PIECE OF FOSSILISED TREE TRUNK FROM BAKER GULLY, IN THE NORTH-EAST CORNER OF McLAREN VALE photo KATE ELMES

"Map?”, I said. “I can get you a map!” And I proceeded to tell him the long tale. Dudley's Association quickly set up a committee, chaired by Jock Harvey, his predecessor at the Association, and on we went. Bill paid his own fare back from York, where his retirement involved him rewriting the geology of a significant slice of north east England, and off we went.

Fortunately, Wolfgang Preiss was still working in the Geological Survey, where he is the senior geologist. So with his estimable assistance and peer approval, the four of us set about finalizing Bill’s work and getting the map published.

This involved some big help from the local member of parliament, Leon Bignell, and assistance from wine-loving cabinet minister, Patrick Conlon. Andrew Rowett of the Geological Survey was also an enormous help and facilitator.

Back-up work came from Bill’s friend Jo Thyer and Jeff’s wife Susan, whom he met away back in our Department days, and who was employed by the same geologist who gave me my job, the late Peter Dunlop.

The Geology Of The McLaren Vale Wine Region is now available from the McLaren Vale Visitor’s Centre, various Vales wineries, and the current version of the old Department of Mines, which is now part of Primary Industries And Resources, South Australia. Whose acronym, PIRSA, is a vast improvement on that of the department I quit all those years years ago, the South Australian Department of Mines and Energy.

THE AUTHOR ADDRESSING THE WINEMAKERS AND VITICULTURERS AT THE LAUNCH OF THE GEOLOGY OF THE McLAREN VALE WINE REGION MAP IN THE BOCCE CLUB, McLAREN VALE photo LEO DAVIS

McLAREN VALE - ITS GEOLOGY IN BRIEF

THE AUTHOR ON THE BEACH AT PORT WILLUNGA, BELOW THE FAMOUS STAR OF GREECE RESTAURANT. THE TOP LAYER IS THE VERY RECENT (PLEISTOCENE) NGALTINGA CLAY, A STICKY WATER-RETAINING FORMATION WHICH IS NOT IDEAL FOR VITICULTURE. NEXT LEVEL IS THE PALE BURNHAM LIMESTONE (2.6 MILLION YEARS), THEN THE CALCERIOUS FOSSILIFEROUS HALLET COVE SANDSTONE (JUST A LITTLE OLDER), AND THE YELLOW-BROWN PORT WILLUNGA FORMATION (23 MILLION YEARS) DIPPING GENTLY SOUTHWARD AT THE FOOT OF THE CLIFF. photo EMILY SHEPHERD ... to view the new map in medium res CLICK HERE

Orogenies, Effluvia and Exposures ... Uplifts, Disruptions and Faultlines ... Chaotic And Random Complexities
by PHILIP WHITE


The Universe is about 13.75 billion years old; the Earth about 4.54 billion.The best simple analogy – the key – to understanding the geology of our planet is to consider it as a pot of stew.

The simmering, molten liquor below is the Earth’s core and mantle, which together are about 6,300 kilometres deep, meaning it’s about that distance to the centre. The globs that form on the much cooler top of the stew gradually enlarge, shrink, dissolve, sink, oxidize, and constantly move about.

We live on this unstable floating crust, which varies from 5 to 75 kilometres thick.

The liquor in the stew of Earth is mainly molten nickel and iron. At the centre, the pressure is so intense that the metals cannot liquefy: there’s a solid metal ball there 2,600 kilometers in diameter. Surrounding that is the liquid part – the Outer Core and Mantle. This varies in fluidity, from quite liquid near the core, to plasticine closer to the crust.The core of the Earth rotates at a faster speed than its crust.

The oldest big rocks on Earth are suspected to the Nuvvuagittuq greenstones on the tundra on Hudson Bay, Canada. These are currently claimed to be 4.28 billion years of age. The oldest tiny rocks found on Earth are the particulate Western Australian zircons, at 4.36 billion years.

To put these vast ages in perspective, the alluvial sand of Uluru – Ayer’s Rock – was being deposited only about 550 million years ago. About 400 million years ago, it was being tilted ninety degrees to the vertical. During the last 300 million years it has been exposed and shaped to its current form.

ULURU - AYERS ROCK - THE GEOLOGICAL, FIGURATIVE, MYTHICAL AND SPIRITUAL NAVEL OF AUSTRALIA WAS BEING LAID DOWN AS SANDSTONE SEDIMENT ABOUT 550 MILLION YEARS AGO. BY THAT POINT IN HISTORY, ALL THE OLD ROCKS SURROUDING AND UNDERLYING McLAREN VALE HAD ALREADY BEEN FORMED. photo NT tOURISM

Australia


The key to understanding Australia is to consider relatively recent times, and commence our natural history about three-quarters of the way along.

Between 570 and 510 million years ago, two globs - East and West Gondwana - joined together, covering one side of the Earth from the Equator to the South Pole.

Almost a mirror-image, a similar sized glob, Laurasia, stretched from the Equator to the North Pole.

180 to 200 million years ago, Gondwana and Laurasia broke apart, and each drifted closer to its Pole.

About 150 million years ago, Gondwana began to break up. It has since broken into Antarctica, South America, Africa, Madagascar, Australia-New Guinea, New Zealand, Arabia, and the Indian subcontinent.

About 80 million years ago, Australia was separating from Antarctica, moving back towards India at about the speed at which your fingernails grow.

We witness the results of this with constant disruptions along the edges of the tectonic plates: in the earthquakes and volcanoes of New Zealand and Indonesia, as this giant slab of ancient rock pushes India north into old Laurasia, forcing the Himalayan mountains upwards.


McLAREN VALE: THE WILLUNGA EMBAYMENT, LOOKING SOUTH. THE PROMINENT RIDGE IN THE BACKGROUND IS THE WILLUNGA ESCARPMENT, FOLLOWING THE LINE OF THE WILLUNGA FAULT. IN THE FOREGROUND IS THE GORGE OF THE ONKAPARINGA, VAGUELY FOLLOWING THE OCHRE COVE-CLARENDON FAULT. THE ROCKS THIS SIDE OF THE ONKAPARINGA ARE FROM THE UMBERATANA GROUP, OLDER THAN 650 MILLION YEARS, AND THE OLD ROCKS ON THE OTHER SIDE OF THE WILLUNGA FAULT STRETCH FROM 520 MILLION YEARS TO 1.6 BILLION. BETWEEN THE TWO, IN THE WILLUNGA EMBAYMENT SLUMP, ARE THE MARINE AND RIVERINE SEDIMENTS OF McLAREN VALE, ALL LAID DOWN DURING THE LAST 56 MILLION YEARS, . photo STACEY POTHOVEN

The Geology of McLaren Vale


McLaren Vale lies in the Willunga Embayment, a wedge-shaped depression between two ancient faultlines in rocks older than 500 million years.

After a great period of inactivity, about 56 million years ago, in the Eocene Epoch, these fault lines reactivated, and the old Neoproterozoic rocks between them subsided, forming an embayment into which younger sediments began to wash down from the mountains to the east, and in from the ocean to the west and south.

These two localized faults are the Ochre Cove-Clarendon Faultline to the north, and the Willunga Faultline to the east.

The western side of the triangle is bordered by the sea: the Gulf St. Vincent.

BOTTOM THIRD OF THE MAP. THE BLACK DOTTED LINE TRANSVERSING THE IMAGE IS THE WILLUNGA FAULTLINE, WHICH MARKS THE WILLUNGA ESCARPMENT. THE ROCKS TO THE SOUTH-EAST OF THIS, IN THE MOUNT LOFTY RANGES, ARE ALL OLDER THAN 520 MILLION YEARS, AND STRETCH BACK TO 1.6 BILLION. THE YOUNGER SEDIMENTARY LAYERS TO THE NORTH WEST, IN THE WILLUNGA EMBAYMENT, ARE ALL YOUNGER THAN 56 MILLION YEARS. ALL VINEYARDS, ROADS, WINERIES AND VILLAGES ARE SHOWN. THE KEY TO THE YOUNGER ROCKS IS IN THE TOP LEFT HAND CORNER OF THE SHEET.

The principal riverine sands to descend from the ancient Mount Lofty Ranges to the east are called the Maslin Sands. These underlie all of the Willunga Embayment. At their deepest, before they disappear beneath the Gulf at Maslin Beach, they have been intersected by water bores more than 300 metres below the surface. They are covered with more recent marine sediments, so they are not oxidized, and at depth remain loose and sandy enough to scoop up for building materials. Where they tilt to the surface, in the north-east corner of the Embayment, they are oxidized, and, in places, have turned to sandstone. As water rich in iron has invaded their interface with the younger sediments and sands above them, ironstone has formed.

About 40 million years ago, the sea moved in to fill the Gulf St Vincent, which stretched as far as Leigh Creek, on the western flank of the Flinders Ranges. On its shallows thickly-vegetated swamps developed. In some places, these have become brown coal.

LOOKING SOUTH-EAST ACROSS McLAREN VALE TOWARD THE WILLUNGA ESCARPMENT, FORMED WHEN THE LAND THIS SIDE OF THE FAULTLINE THERE SLUMPED, TO BE REFILLED WITH SANDS FROM THE RANGES WHICH ONCE TOWERED BEYOND, AND VARIOUS LAYERED SEDIMENTS FROM THE OCEAN, OUT OF FRAME TO THE RIGHT photo MILTON WORDLEY.

For 25 million years this Tertiary ocean covered the Nullarbor, the Mallee and the South East of South Australia. Hundreds of metres of mud, fossils, and lime were deposited.

15 million years back, the sea retreated, only to invade again five million years ago, this time depositing sand and marine clay on the Adelaide Plains, the Mallee and the Limestone Coast. These sands and clays formed the aquifers of Adelaide, Willunga and Noarlunga, which now contain mainly fresh water.

There are two aquifers in the Willunga Embayment. These fill with fresh water which flows in creeks down from the ranges and the escarpment. When these creeks reach the Willunga Fault, much of their water disappears underground into that buried fissure, to refill the aquifers, pushing the brackish water back out beneath the Gulf.

About 2.5 million years ago the most recent major ice age commenced. The polar ice caps grew very large, taking up much of the planet’s water. 60,000 years ago, when the icecaps were enormous, the waterline was 120 kilometres distant. One could walk to Kangaroo Island. The gulf was a vast marshy plain with the River Vincent flowing down its centre, bringing south more sands, gravels and clays. Giant marsupials grazed here.

As the ice caps expanded and contracted, the sea repeatedly came and went, laying down various clearly delineated sequences of marine sediment. When it retreated, cold, windy, desert conditions prevailed, during which windblown silts were laid down, and lines of sand dunes were left. The reefs below the water off Port Noarlunga are remnant dunes from these times.

Other sediments washed down from the Mount Lofty Ranges to the east, across the Willunga Faultline into the Embayment, and on into the Gulf St. Vincent.

Over the millennia, various uplifts, disruptions and erosional effects have exposed these riverine and marine sedimentary sequences in an apparently chaotic and random manner, making the surface geology very complex, varying from one site to another.

GEOLOGIST JEFF OLLIVER AND THE AUTHOR EXAMINING THE UNCONFORMITY IN THE CUTTING NEAR CHAPEL HILL. THE RED NORTH MASLIN SANDS (50-56 MILLION YEARS) SIT DIRECTLY ATOP THE PALE BURRA GROUP (OLDER THAN 750 MILLION YEARS). THERE ARE 700 MILLION YEARS MISSING. photo KATE ELMES

The Geology Of Yangarra Estate


Yangarra’s geology is sedimentary.

Yangarra lies against the foot of the Willunga Escarpment on the Willunga Faultline near the eastern extreme of the Willunga Embayment, further from the Gulf than any other major McLaren Vale vineyard.

Yangarra’s sediments were deposited by streams flowing east-west from the Ranges down to the Gulf, and not by the west-east intrusions of the ocean which filled much of the Embayment. They are riverine, not marine.

THE AUTHOR AT AN OLD IRONSTONE PIT AT YANGARRA. HE IS INDICATING THE 600 MILLION YEARS PLUS BEDROCK BELOW THE GRAVELLY, QUARTZY, 50 MILLION YEARS PLUS NORTH MASLIN SAND BY HIS KNUCKLES - AN UNCONFORMITY. THIS IS THE ONLY KNOWN EXPOSED EXAMPLE OF THIS OVERLAY AND THE 500 MILLION OR SO YEARS OF GEOLOGY WHICH IS QUITE SIMPLY MISSING. IT'S NOT THERE photo- KATE ELMES 

The major geological formation below Yangarra is a thick layer of North Maslin Sand. This was washed down during the Eocene Epoch (34-56 million years ago), across the fault, from the very ancient sandstones (up to 1.6 billion years old) of the Mount Lofty Ranges. Twenty-five kilometers to the west, on the coast near Maslins Beach, this same yellow, orange, red and brown sand is mined for use as construction and decorative sand.

In those 150 metre deep pits, where the sands are not oxidized, they are still loose and easily dug by machines.

But where the North Maslin Sand tilts upward to the surface at Yangarra, it's exposed to oxygen and weather, which has turned it to stone. The penetration of iron-rich water over the millennia has converted much of this cap to ironstone. There are ironstone ridges running north-south through the vineyard, growing fruit of great intensity and strength.

The North Maslin Sand reaches its north-easterly extreme beyond Baker Gully about five kilometres north east of Yangarra. Here, this thinning iron-cemented sandstone lies directly atop the very old meta-sediment of the Neoproterozoic Burra Group, which is older than 750 million years. In the roadcut on Chapel Hill Road, one can place a finger on the unconformity where 700 million years of geology is simply missing. The older Neoproterozoic rocks were deposited before Gondwana had formed and moved itself to the South Pole, away back when multi-cellular life was only just beginning.

1946 VINTAGE GRENACHE BUSH VINES IN THE SEMAPHORE SANDS OF THE HIGH SANDS VINEYARD IN THE RECORD HEAT BLITZ OF 2009. THE NEW YANGARRA ORGANIC VITICULTURAL REGIME NOW ENSURES THAT NO SAND REMAINS BARE OF GRASSES AND HERBS, WHICH WILL DRAMATICALLY REDUCE REFLECTED HEAT DAMAGE WHENEVER ANOTHER HEATWAVE OF SUCH VICIOUSNESS OCCURS photo PHILIP WHITE


At Yangarra’s western extreme, where the North Maslin Sand begins to plunge gently to the coast, an overlying clay layer has formed. This is covered by a dune of aeolian, or wind-blown Semaphore sand, blown here in the last 10,000 years. Although it was not deposited by the sea, the Yangarra crew humorously call it The Beach.

In contrast, at the eastern side of the vineyard, along the faultline below the range, the thinning North Maslin Sand is covered in bits of quartzite and rounded riverine siltstones and sandstones in loose sand and clay, depending on when it was washed down, and from where.

This alluvial fruitcake, collectively called the Kurrajong Formation, was broken by water and ice from the 750+ million years old Burra Group formations which once towered mightily in the mountains to the east of the faultline.

It was dumped during the Pleistocene (10,000 – 2.6 million years ago), when glacial action, and vast meltings, were repeating widespread.

Interestingly, these rounded riverine stones and glacial pebbles are thick in the free-draining sandy soil beneath the Yangarra Roussanne vineyard. These rocks are similar to the galets – the rounded riverine and glacial stones – transported from the Alps and deposited about two million years ago in the Northern Rhone around Hermitage. These galets are highly regarded by Rhone Roussanne makers.

PETER'S CREEK IS A MERE TRICKLE AS IT FLOWS THROUGH THE YANGARRA FARMHOUSE FRONT GARDEN. FIFTY MILLION YEARS BACK, IT'S GIANT FOREBEAR WAS A CONDUIT FOR MASSIVE EFFLUVIA, USING ENORMOUS ENERGY TO WASH NORTH MASLIN SANDS AND GLACIAL DROPSTONES FROM THE CARBONIFEROUS-PERMIAN ONTO THE BASE OF THE WILLUNGA EMBAYMENT photo PHILIP WHITE

Peter’s Creek flows through the front garden of the old Yangarra farmhouse. Upstream, across the fault at the crest of the escarpment, lies a discrete formation of geology from the middle of that 700 million year gap visible in the cut on the ironstone knoll. This is a basin from the Carboniferous-Permian period, about 300 million years ago. All the other geology from that gap is still missing. This incidence is freaky.

To add complexity, this formation is peppered with dropstones. These are stones from great distances away, which have been picked up by glacial ice, to be deposited as dropstones when and where the ice melts.

It will involve more forensic geological work, but this rare incidence of the Carboniferous-Permian may explain the peaty aroma of some of the local wines which grow along the ridges and north in Baker Gully where the North Maslin Sands are close enough to the surface to be near the vine roots. The Carboniferous-Permian is the epoch of mighty coal and peat swamps; in this formation most of the world’s oil shale and oil reside.

The aroma could also come from the lesser bituminous formations laid down 40 million years ago. To the north of Yangarra in Baker Gully there’s a quarry which shows an exposed bituminous layer; above and nearby is a field from which vineyard ripping has drawn up chunks of fossilized timber. These fossils appear to be coniferous in type: they resemble native pine, or even Huon Pine.

Although vine roots cannot absorb oil, the aroma of this bituminous layer would readily penetrate the clay and sand above, to influence the flavour of the water tapped by the vine roots.

It is this amazing complexity, with fragments of stones from so many eras and locations mixed with those that have actually formed on site, that makes Yangarra Estate’s suite of vineyards so unique.

Now the ground work has been done, further geological forensics will help uncover more detail, and more keys to the secrets of the beautiful flavours that this complex, fascinating geology delivers.

PETRIFIED CONIFER TIMBER FROM BAKER GULLY. THE SHINY SPECKS ARE QUARTZ. THIS COULD WELL HAVE BEEN WASHED DOWN PETER'S CREEK IN A MAJOR EFFLUVIUM.photo PHILIP WHITE