Golden Bay VI: The Karst Country of the Cowin Road

The stark and beautiful juxtaposition of bared rock, cropped turf and the luxuriant growth of remnant lowland forest with nikau palms on the Cowin Road/Paturau River west of Golden Bay.
The stark and beautiful juxtaposition of bare rock, cropped turf and the luxuriant growth of remnant lowland forest with nikau palms on the Cowin Road/Paturau River west of Golden Bay.

I thought this little strip of coast so far from 'anywhere' was one of the most amazing places in New Zealand. Of course the weather helped and we were probably there for less than an hour.

The swooping gravel road and our companions speeding away for cold beers.
The swooping gravel road and our companions speeding away for cold beers.

The land along the coastal strip south to Kahurangi Point was cleared by hand before the advent of bulldozers and JCBs. It was done in large part by three generations of the Richards family who settled at Paturau.

 

"They had very little money. They would buy a couple of hundred acres, clear and grass it, then buy some more. Initially they bought some poor quality calves but once they had bought two or three blocks, they were on their way. From the 1920s to 1940s, about six men were employed to clear the bush. They used axes and saws and then stacked up the trees and burnt them.  They would fell 100 foot rimu trees and set a fire at one end which would burn for a week leaving a long streak of ash which fertilised the ground."

 

Remnant bush and sheep paddocks below bluffs of limestone on the road to Antanori.
Remnant bush and sheep paddocks below bluffs of limestone and mudstone on the road to Antanori.

Farm work was supplemented with work in the local coal mine to bring in a bit of cash.

 

Between 1910 and the 1960s the Richards would take cattle to the Annesbrook abattoir from Paturau on a seven-day drove.

 

"We'd bring the cattle up from Rata Creek to Paturau and then time it so we had a full moon for the tides. We'd leave at moonlight, walk along the mudflats at Westhaven [Whanganui Inlet] and through the Pakawau bush. That was a long day but the first part of the trip was more leisurely because we owned land at Ferntown and Takaka. We'd rent paddocks for the night for the rest of the drove."

 

(See The Prow: Paturau)

Wind-shaped close-knit shrub and flax on the Cowin Road south of Mangarakau
Wind-shaped close-knit shrub and flax on the Cowin Road south of Mangarakau

Each bend of the road seemed to offer something new. Here the scour of the wind and a reminder of a bad blow in the short days of winter, with fantasies of driving back through the dark, lights picking out the uncertain edge of the road in the lashing rain, the ground sodden and threatening to slip and slide away into the sea.

 

I was reminded of parts of the Isle of Skye in the Western Isles of Scotland - a long single track road that leads to somewhere that feels a place apart and yet has its own integrity, that feels like a community carved out and cemented by the struggle with land and weather, secure of its own precarious place in the world.

Mudstone formed from Miocene hemipelagic mud and distal turbidites overlying the upper layer of the Takaka/Paturay limestone beds on the Cowin Road.
Mudstone formed from Miocene hemipelagic mud and distal turbidites overlying the upper layer of the Takaka/Paturay limestone beds on the Cowin Road.

Here on this far north-west corner of the South Island you get a really intense sense of being on an island - the Tasman Sea to the west stretching over 1000 miles to Australia. To the east the limestone bluffs and behind them mile upon mile of uninhabited, rugged, forested hills that rise up to the heights of the Wakamarama Range and Mt Stevens at 1 213 metres.

 

Its a 10km tramp through pathless, roadless, arduous and lumpy country to the rich dairy farms of the Aorere River valley. From the end of the Cowin Road and the lighthouse at Kahurangi Point there are 40 kilometres of untouched, unpeopled coast to the Karamea-Kohaihai gravel road that comes up from Westport.

The deceptively placid water of the Otuhie River, fed upstream by the Otuhie Lake.
The deceptively placid water of the Otuhie River, fed upstream by the Otuhie Lake.

The Karst Country

The Kahurangi National Park is one of the most geologically complex areas of New Zealand. On the far west of the park are granites variously overlain by limestones, marbles, conglomerates, siltstone and coal measures (Kahurungi National Park Management Plan p.17).

 

The high peaks and areas like the Gouland Downs are made up of eroded and incised peneplains ('a low-relief plain representing the final stage of fluvial erosion during times of extended tectonic stability,' Wikipedia).

Farm buildings on the Cowin Road south of Mangakarau
Farm buildings on the Cowin Road south of Mangakarau.

The Takaka and associated Paturau Limestones were laid down when most of nascent New Zealand was submerged beneath warm seas 55-25 MYA - in the Late Cretaceous/Cenozoic era. (Richards 2003 p.19)

 

The Takaka Limestones were metamorphised by granite intrusions and tectonic pressure into the so-called 'Arthur Marble 2'  (after nearby Mt Arthur) which is a Late Ordovician black limestone and calcareous mudstone.

Post boxes on the spur road to Otuhie Lake on the Cowin Road
Post boxes on the spur road to Otuhie Lake on the Cowin Road.

Marble from the Kairuru Quarry (1911 - 1912) was mined and transported to Wellington for use in building parliament (Richards 2003 p.38).

 

The most spectacular and accessible karst country is inland from Karamea (50-60km south of Paturau) - but only accessible from the Buller valley and Westport much further south still. Here there are huge cave systems and the spectacular Oparara limestone arch.

 

(Source: This and subsequent sections of this page draw heavily on the MA Thesis in Environmental Science of  Danette Richards, Geomorphological and Environmental Studies of Karst, Northwest Nelson, New Zealand  - University of Canterbury, NZ: 2003 - and is referred to above and below as 'Richards 2003').

Remnant bush of trees ferns, nikau palm and kraka pullulate in the translucent, limpid light of the Tasman Sea.
Remnant bush of trees ferns, nikau palm and kraka glitter in the translucent, limpid light of the Tasman Sea.

 

Little mention is made anywhere on the internet of the Cowin Road and the Paturau limestones. It appears remarkably and brilliantly overlooked but for a few cavers. It is briefly acknowledged as one of the three areas of karst landscape in New Zealand - see below.

 

This scant regard for the Paturau karst landscape is due to its remoteness and exclusion the Kahurangi National Park and the Northwest Nelson Forest Park. It also has little economic significance in that its aquifers are not important for centres of population and farming - like Takaka and Motueka (the latter with its intensive apple, hop and tobacco industries) - and its landscape is not on the main tourist trail.

 

After all, the Paturau is hidden away at the end of a 25km gravel road that winds through forest, crosses numerous inlets and the swamps of Mangarakau never passing a house let alone a cafe or shop. It is wild, isolated country and yet it feels remarkably homely.

 

The bush remnants of fern tree, nikau palm and karaka - Corynocarpus laevigatus - seem to glisten and pullulate against the stark matt colours of the mud- and limestone cliffs on the Cowin Road westv
The bush remnants of fern tree, nikau palm and karaka (Corynocarpus laevigatus) stark against the matt colours of the mud- and limestone cliffs on the Cowin Road

'Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterised by underground drainage systems with sinkholes, dolines, and caves.'

 

Wikipedia: Karst

 

A huge cleft in the limestone where a slab has fallen from above after being undermined from underneath?
A huge cleft in the limestone where a slab has fallen from above after being undermined from underneath.

The etymology of 'karst' is complicated,

 

According to the prevalent interpretation, the term is derived from the German name for the Kras region (Italian: Carso), a limestone plateau surrounding the city of Trieste in [north-eastern Italy] (Wikipedia: Karst).

 

Sentinels of blackened limestone with lichen tops stand mute on a hillside on the road to Antinori.
Sentinels of blackened limestone with lichen tops stand mute on a hillside on the road to Antinori.

Karst landscapes are formed when rainfall picks up carbon dioxide from the atmosphere and the soil (where there is 100 times more carbon dioxide than in the atmosphere).

 

This mixture forms carbonic acid which erodes limestone. Erosion is fastest near the overlying soil layer where the acid is strongest. Ninety per cent of dissolution takes place in the top 10 metres of limestone. The amount of rainfall  and the purity of the limestone both affect the rate of erosion.

The karst country of the Cowin Road beyond Paturau with remnant forest in the water seepage beneath the cliffs
The karst country of the Cowin Road beyond Paturau with remnant forest in the water seepage beneath the cliffs

Karst systems have an amazing intimacy. They are like rock-gardens before rock gardens were invented - think of the limestone pavements of Malham Cove in the Yorkshire Dales in the UK or the Burren on the north west coast of Ireland.

 

They are landscapes within landscapes and have something of Chinese ink brush paintings of mountains and gorges. And they are like 'land art' before the fumbling hand of humans intervened.

Tree palms and wind blown manuka shield a spring-fed pond beneath the limestone bluffs
Tree palms and wind blown manuka shield a spring-fed pond beneath the limestone bluffs.

They are full of mystery and indeed terror. The beautiful zen-like quality of the surface hides great sinkholes (see picture of the the 183m deep Harwood's Hole near Takaka at end of this page), swallowed streams, cave systems - drowned and not - of immense complexity and full of the darkness and pinchpoints of nightmares. 

 

I remember watching with horrified fascination as a group of divers geared-up in cumbersome suits, a rope holding them together, to enter the freezing waters of a south-west French gouffre - resurgence - to disappear into the eternal underwater dark, beneath the huge weight of rock pressing down from above, their last air bubbles breaking the surface of a pulsing pool hidden in deep forest.

The spectacular karst country of the Cowin Road: a mustone cap with revealed karst features of the topmost beds of Takaka limestone which are the hardest and purest.
The spectacular karst country of the Cowin Road: a mudstone cap with revealed karst features of the topmost beds of Takaka limestone which are the hardest and purest.

Limestone derived soils are fertile but fragile. The soils formed from them 'are the residues remaining after solution processes have removed the balance of the rock' (Richards 2003 p.31).

 

Soils derived entirely from carbonate residues are known as 'rendzinas'. They are fertile but lacking in phosphate and normally lie directly on bedrock with no subsoil. They resistance to erosion comes from their high fertility, organic content and good structure. The lack of surface water and potential for drought are serious limitations to intensive farming.

This bed of rock above the limestone is quite distinct and marked with strange holes apparently scoured horizontally into it. (Did the bedding plain once lie flat on a river bed to be scoured by bould
This bed of rock above the limestone is quite distinct and marked with strange holes.

 

Karst soils develop very slowly because solution takes away most of the weathering residues. The thin veneer of soils is  prone to degradation and erosion or loss simply by being swallowed or washed down surface openings like dolines and fractures.

 

Rainfall on the Cowin Road is in the region of 2.25 - 2.50 metres (98.5 inches) a year (that's about double the rainfall of Glasgow in the UK).

 

Harry and Laurence Richards of Paturau Farm were early advocates of post-war aerial phosphate top dressing. Says Harry,

 

"There was a high price for wool at the time so farmers had a bit of extra money. We bought some fertilizer for a property at Kaihoka [on the north side of Whanganui Inlet] we were developing and thought the plane would be able to land on the beach but it couldn't. It took us a year to construct an airstrip and in the meantime the sacks of phosphate had become like concrete."

 

Better roads were driven through in 1962 , more landing strips have been laid down and since then 'tonnes of super phosphate, lime and potash have been spread, boosting the productivity of the farm'.

The carbonate rocks of the Arthur Marble in north west Nelson host New Zealand's most notable karst landscapes.

 

These include New Zealand's largest spring (Te Waikoropupu Springs), the deepest, longest, and possibly oldest caves such as Nettlebed (889m deep, 25km long, and over 700,000 years old), and the largest subterranean rivers in the country.

 

The karsts of the Takaka region are renowned for the 176m free-fall shaft of Harwoods Hole, the scenic Marble Plateau Karst, the resurgence or source of the Riwaka River and the numerous and extensive cave systems such as Greenlink (approximately 360m deep), Middle Earth, and Perseverance (Richards 2003 p.8).

 

Like Paolozzi modernist chess pieces marching down the hill. Limestone outliers stark against the Cowin Road sheep paddock
Like Paolozzi-inspired modernist chess pieces marching down the hill: limestone outliers stark against the Cowin Road sheep paddock.

 

Interestingly, Maori settlement on karst areas was limited because of the rahui (embargo) emplaced on karst areas by local iwi.  In Maori mythology Karst, with other landscapes, represents Papatuanuku (the Earth Mother) and the karst topography and,  in particular, caves are thought to be where the world and universe come together. It is believed that karst landscapes were associated with the presence of a spiritual entity or taipo (or goblin) which was said to reside in the Canaan area between Takaka and Motueka (see Richards 2003 p.37).

 

This karst landscape on the bluff to the north of the Puturau shows an earlier stage of karst formation. Rinnenkarren (runnels) are visible on the partly unmantled limestone at the bottom of the photo
This karst landscape on the bluff to the north of the Puturau shows an earlier stage of karst formation. Rinnenkarren (runnels) are visible on the partly unmantled limestone at the bottom of the photo (see detail below).

The terminolgy of  karst features is drawn from German.

 

The 'karrens' - forms of surface erosion of limestone pavements and blocks - run into a bewildering array of forms and sub-forms (first, second and third order). They are supplemented by 'cockling', 'flutes and scallops', and 'dirt polygons and rims'. At times the language at times gets so 'axially ablated' that it appears to lose all meaning (see example below).


The language of the karstite at time become as labyrinthine as the caves formed by carbonic acid. The above from From Sedimentary structures, their character and physical basis, Volume 2 p.229
The language of the karstite at time become as labyrinthine as the caves formed by carbonic acid. The above from From Sedimentary structures, their character and physical basis, Volume 2 p.229.
(Detail) Rinnenkarren (runnels) are visible on the partly unmantled limestone
(Detail) Rinnenkarren (runnels) are visible on the partly unmantled limestone.

There is a nice collection of photos of different karstitic forms here .

Here the Rinnenkarren (runnels) are more developed and turning into wide kluftkarren (grykes) in more exposed limestone at the top of the bluff.
Here the Rinnenkarren (runnels) are more developed and turning into wide kluftkarren (grykes) in more exposed limestone at the top of the bluff.

But these things are clearly important. With regard to the spitzkarren it seems that the classic form of this is a vertical piece of limestone with a sharp edge or projectile 'nose cone'.  And the sharper the cone the more indication that the karren was formed in an unmantled manner, so to speak. That is, it was not covered with soil or debris.  Karren formed beneath the soil have a more rounded and smooth shape (see Sedimentary structures, their character and physical basis, Volume 2 p.229).

Unmantled karst forms - karren. The overlying soils and interveing rocks anve been dissolved away to leave these sentinels on the steep hillsides alongside the Cowin Road
Unmantled karst forms - karren. The overlying soils and intervening rocks have been dissolved away to leave these sentinels on the steep hillsides alongside the Cowin Road
From Sedimentary structures, their character and physical basis, Volume 2 p.230
From Sedimentary structures, their character and physical basis, Volume 2 p.230.
A huge exposed limestone slab with vertical channels eroded into it by acidic action.
A huge exposed limestone slab with vertical channels eroded into it by acidic action - a spitzkarren of sorts. Sheep have contributed by eroding soil away from the bottom of the slab.

Without more guidance it is hard to know how the distinctive limestone forms of the Cowin Road were formed. It would seem from the lack of sharp edges and projectile shapes that there were formed with a soil covering. This was in all likelihood a soil covering supporting thick lowland forest.

 

The inky black surfaces of these karren contrast sharply with the close -cropped grasses around them and the brilliant greens of the bush plants of the nikau palms and karaka
The inky black surfaces of these blunt spitzkarren contrast sharply with the close-cropped grasses around them and the brilliant greens of the bush plants of the nikau palms and karaka.

You wonder how quickly these forms came to the surface with the removal of the forest cover in the 20th century. Were they revealed as the trees came down or have they been revealed subsequently by erosion and sheep and cattle grazing?

 

This latter seems unlikely as limestone soils are generally thin. Maybe these forms have been here for thousands upon thousands of years hidden by forest. The ample rainfall of the coast gradually dissolving out the limestone with atmospheric and soil-based carbon dioxide.

 

It is unlikely that they have been affected by glacial karst processes as little of the north of the South Island was under ice in the Ice Ages. It is also unlikely that the hillside karst features were affected by sea level changes. If anything glacial rebound in the Southern Alps might be pushing the northern coasts of the South Island downwards.

 

So other than 'aggressive dissolutional processes' working over millenia we have few other clues as to how the karst columns and outliers of the Cowin Road/Paturau River were revealed.

 

Kluftkarren - grykes - are clarly visible running down the large pinnacles in the middle of the photo.
Kluftkarren - grykes - are clearly visible running down this large pinnacle.

Looking back through my photos there are clearly different bands of mudstone and limestone at Paturau/Cowin Road. The bluffs above the river show wind erosion of close bedding plains - somewhat like the erosion as Punakaiki (Pancake rocks).

 

Perhaps it is the exposed position of these rocks that has led this to become so pronounced but it is interesting that karst columns and outliers further south down the Cowin Road do not show bedding plain erosion. This would suggest that either these are much less exposed to the prevailing westerlies and their sand/grit/brine load or that they are made of tougher - more marbelized - limestone.

Sheep and wild goats grazing side-by-side amonst the fantastic rock formations of the Cowin Road south of Mangarakau
Sheep and wild goats grazing side-by-side amongst the fantastic rock formations of the Cowin Road south of Mangarakau formed from the hardest and most pure beds of Takaka limestone.

Delving further into this it seems that the Takaka Limestones - of which Paturau is a part - were laid down between 22 and 13 MYA through marine sedimentation processes that differed over time depending on sea depth, currents and climate.

 

Sedimentation started with glauconitic calcarenite and calcareous conglomerates and progressed in the middle measures (of the total beds that vary from 5 to 100m in thickness) to bivalve-briozoan-barnacle-foraminiferal-algal calcarenites which in turn were completely dominated by briozoan calcarenites of the mid-outer shelf depths  (See Kamp, P. and Neslon C. Nature and Occurrence of Modern and Neogene active margin limestones in New Zealand NZJGG 1988 Vol 31, N.1 p.11).

Sculpted by water and wind: karrren and wind-bent tree
Sculpted by water and wind: karrren and wind-bent tree

What this seems to suggest is that the Takaka limestones are made up of three distinct beds that shift from rough conglomerates to shell-built limestones to limestones formed from briozoa (tiny sea organisms less than 0.5mm long). The bottom bed is the least pure form of limestone whilst the topmost and most recent is the purest being 95-98% Calcium carbonate (ibid  p.11)

 

Once laid down the limestone was then overlaid by a sudden Miocene 'influx of hemipelgaic mud and distal turbidites' - that is, non-calcareous deposits that formed mud- and sandstones.

 

These differences are accounted for by the 'transgressive-regressive cycle' which in effect means that sea levels rose and fell and as the water depth and proximity to land-based deposition by river varied different forms of calcium, mud, sand, and gravels deposits were laid down.

 

There are two distinct layers of rock. The tops are a less finely-bedded sand- or mudstone that weathers to a grey finish and lacks karstic features. Below is a limestone/marble layer that achieves ka
There are two distinct layers of rock. The tops are a less finely-bedded sand- or mudstone that weathers to a grey finish and lacks karstic features. Below is a limestone/marble layer that achieves karst forms and weathers to inky black.
Detail of photo above showing spitzkarren below the layer of overcapping rock on the bluffs behind.
Detail of photo above showing spitzkarren below the layer of overcapping rock on the bluffs behind.

So in effect within the Takaka beds there is a profile from the bottom up of increasingly pure forms of limestone covered by a cap of mudstone. In many places these beds have disappeared completely through erosion. But in others they remain in various stages of erosion.

 

These various limestones and mudstones were then subjected to metamorphic pressures - the sheer weight of accumulation, horizontal compression through tectonic forces and heating through granite intrusions from below.

 

At Paturau/Cowin Road the limestone/marble beds are overlain by what looks like a flaky mudstone.

Gnarled limestone bluff above the Paturau River
Gnarled sandstone and limestone at the top of the bluff above the Paturau River

The position of the bluff edge has presumably been in part determined by faulting in the area - although this is more intense in the Takaka area than the Paturau River  - for example - the escarpment of Takaka Hill is formed along a major faultline - the Pikikiruna Fault.

 

Takaka Hill is nearer to Marlborough Sound to the east which is formed from the continuation  (transfrom basin) of the great Alpine Fault that results from the collision of the Pacific and Australian plates.

 

The Takaka Hill Fault and the fault that helped form the bluff line at Paturau and Mangakarau run almost exactly parallel.

Here the bedding plains indicate  purer limestone and the effects of wind erosion in the bluff above the Paturau River with acres of ultramarine sky.
Here the bedding plains indicate purer limestone and the effects of wind erosion in the bluff above the Paturau River with acres of ultramarine sky.

The most distinct karst formations develop in the purest and hardest limestone - that is, in this case of the Takaka sequence in the top-most beds below the mudstone cap.

 

This would perhaps explain why the karst columns and outliers are relatively high up the slopes of the bluff.

Close-up of the bedding plains of the limestone bluff above the Paturau River
Close-up of the wind and water eroded bedding plains exposed to the full force of the Tasman Sea westerlies of the limestone bluff above the Paturau River - reminds me of the rocks at Panakaiki (Pancake Rocks). Click for link to my Panakaiki page.

The different hardness and purity of the limestone beds is particularly evident along the perpendicular bluff cut by the Paturau River (which may follow a transverse fault).

 

Here there seems to be a harder layer of limestone beneath the forested shelf with  a more dissolved layer beneath it and beneath that a more rubbly layer.

 

The undercutting action of the Paturau here leads to a particularly steep slope and it may be that karst outliers here once detached from the bed rock tumble into the river.

The layering of limestone and what appears to be a mud- or standstone above.  The hanging foreest of nikau palm marks the divide on this high bluff above the south side of the Putarau River
The layering of limestone and what appears to be a mud- or sandstone above. The hanging foreest of nikau palm marks the divide on this high bluff above the south side of the Putarau River
The bluff as it turns the corner into the lee of the prevailing westerlies with a fallen pillar of limestone in the Paturau river.
The bluff as it turns the corner into the lee of the prevailing westerlies with a fallen pillar of limestone in the Paturau river.

Richards (op cit pp8-9) relates that the Takaka Hill limestone was uplifted by 1km due to tectonic pressures and faulting on either side of it.

 

To the west of Takaka Hill the land has been uplifted further through mountain building associated with the colossal forces of the collision of the Pacific and Australian plates forming the Haupiri and Wakamarama Ranges.

 

Presumably the uplifted mudstone and limestone on this land has long been eroded away due to greater rainfall and limited glaciation at greater altitude with the exception of the dolomite outcrop on Mt Burnett.

Detail of photo above where  horizontal and vertical erosion are visible with developing grykes.
Vertical erosion is visible with developing grykes on the Paturau River bluff which is too undercut to maintain limestone outliers.

At  Paturau/Mangarakau it is possible that a further segment of limestone was uplifted to form the chain of bluffs that run from Cape Farewell towards Kahurangi Point.

 

At a lower altitude these have been subjected to less intense processes of erosion. At the edges of the bluff scarp the hard limestones have been revealed with the regression of the scarp edge and over a vast period of times the limestone has been etched away by carbonic acid.

 

To complete the process the scant but fertile soil formed fell away around the remnant limestone pillars and karren and these latter were eventually revealed by the removal of forest cover by 19th and 20th century clearance and agriculture.

Here the eroded horizontal layers of bedding plain are verey clear while vertical fissures can also be made out on the bluff above the Puturau
Here the eroded horizontal layers of bedding plain are very clear while vertical fissures can also be made out on the bluff above the Paturau

Trying to unravel the story behind the formation of the spectacular Cowin Road/Paturau River karst country maybe somewhat undermines the romance of the place but for me at least it helps explain the way it is.

 

And it is both a salutary reminder of the immense periods of deep time required to make landforms and landscapes and their fragility when we start to muck them about without understanding where they came from.

Sea-formed karren at Paturau Beach (http://nzfrenzysouth.files.wordpress.com/2013/
Sea-formed karren at Paturau Beach (Courtesy of http://nzfrenzysouth.files.wordpress.com/2013/ - click for link)

We never did get down on to Paturau beech but I came across some lovely photos of the wave-sculpted forms (below) we missed.

 

We were merely birds of passage who had stumbled across this beautiful corner of the north west South Island. Time was pressing. The day was using up. We moved on back over the now tiresome bends and causeways of the 'Dry Road' back to Golden Bay.

Limestone rock pools  at Paturau Beach (Courtesy of http://nzfrenzysouth.files.wordpress.com/2013/ - click for link)
Limestone rock pools at Paturau Beach (Courtesy of http://nzfrenzysouth.files.wordpress.com/2013/ - click for link)
Keyhole formations in Paturau beach limestone http://nzfrenzysouth.files.wordpress.com/2013/
Keyhole formations in Paturau beach limestone (Coutesy of http://nzfrenzysouth.files.wordpress.com/2013/ - click for link).

The biggest area of karst landscape in the South Island lies to the east of Takaka on the heights of Takaka Hill. This faulted landscape holds many doline and the huge and terrifying Harwood Hole.

 

I insisted on stopping on our drive in from Nelson to take a few pictures of the marble plateau karst on top of Takaka Hill (see below).

t Caanan Downs at the top of Takaka Hill
Marble Plateau Karst country at Caanan Downs at the top of Takaka Hill where large 'solution dolines' (depressions) form the characteristic karst relief.

You wonder where all the water goes from this large area with not a stream in sight. A day later we found out when we drove up to the Te Waikoropupu Springs. The story continues on the next page.

Marble Plateau Karst
Marble Plateau Karst
View of the entrance pit of Harwood Hole, New Zealand, taken from the bottom. It is 183 meters (about 600 feet) deep (Courtesy Dave Bunnell WikiCommons)
View of the entrance pit of Harwood Hole on Takaka Hill, New Zealand, taken from the bottom. It is 183 meters (about 600 feet) deep (Courtesy Dave Bunnell WikiCommons). See guy on rope for scale. Harwood's Hole has an overall depth of 357m.
Limestone bluff beneath the old cement works at Ligar Bay.
Limestone bluff beneath the old cement works at Ligar Bay, east of Pohara.