WEGA in the North West Highlands Geopark

WEGA, the West of England group of the Geologists’ Association, organised an excursion to the classical geology area of the North West Highlands of Scotland in April / May 2019. “Organise” is putting it rather highly – participants had to arrange their own accommodation in Ullapool, also their transport to the village. And the leader, geological teacher and mini bus driver was supplied by the Geopark. Also the Geopark provided the mini bus! All in all an easy way to organise an excursion.

But a very effective one – the Geopark looked after us very well.

But

Santander and Bordeaux

On 17th May 2013 Chris and I drove to Portsmouth to catch the Brittany Ferries “Cap Finisterre” to Santander. We were off on another of our retirement holidays.

This one was inspired by a geological excursion, organised by the Geologists’ Association (the GA) to the Bordelais looking at the areas geology and its affect on the main agricultural product of the region – wine. We could have done the excursion by flying to and from Bordeaux, but we decided to make it more of an adventure by using the ferry, staying near Santander for almost a week so we could explore a part of Spain we knew not at all, drive to Bordeaux for the excursion, drive back to Spain and Bilbao, visit the Guggenheim, then back on the ferry and home. we would be away from home for just sixteen days. And we would be able to carry a reasonable quantity of wine back with us!

To make the bits of the blog more manageable I am splitting it up into pages which you can get to from the links below and the Menu at the top and bottom of all the pages.

 

Lierganes

A look at the village we stayed in.

Caves, Beaches and Tourist Traps – Saturday 19th May

Paleolithic cave paintings, a lovely (cold) beach and Cantabria’s equivalent of a Cotswold village.

 

Hawaii – part III – More Hot Rocks

Until 1969 most of the major volcanic activity on Kilauea was at the summit caldera as described in the previous post. But in that year another centre of activity began at what is now known as Mauna Ulu. This was the start of a trend for volcanism to move to the south East. Currently most activity is at Pu’u ‘O’o.

Activity started along a fissure with lava fountaining out of a mile long crack.

The fissure of the 1969 eruption
The fissure of the 1969 eruption

Most of the lava went downhill as lava flows but there was a spatter upslope which has left a distinctive “Spatter Rampart”.

Detail of Spatter Rampart
Detail of Spatter Rampart

Fissure with associated Spatter Rampart
Fissure with associated Spatter Rampart. The trees are growing in the fissure.

The fissure and associated lava and tephra field
The fissure and associated lava and tephra field

The fountaining lava gave rise to huge deposits of cinders, many of which have a colourful irridesence.

Iridescent lava cinders
Iridescent lava cinders

Also there are abundant streamlined droplets of flying lava called “Pele’s Tears”.

Pele's Tears
Pele's Tears

In a few months the activity had concentrated at the future site of Mauna Ulu and the lava shield began to build. The surrounding countryside was covered with lava and lava flows ran towards the sea. Further along the “Chain of Craters Road” you can see where lava flows from Mauna Ulu ran over a cliff and down towards the sea building lots of new land.

Lava flows came over this cliff to form the land I am standing on
Lava flows came over this cliff to form the land I am standing on

Nearer to Mauna Ulu itself the lava flows covered a tree covered landscape. Often the trees leave a memory of themselves in the shape of “Lava Trees”.

Chris with a lava tree
Chris with a lava tree. Note the mould of a tree on the left. There is another mould above Chris's head.

The lava comes against the tree and solidifies immediately due to the water content of the tree. More lava solidifies and the rest of the molten lava flows past the solid mass. Meanwhile the tree burns away just leaving its shape behind. When the lava stops the level drops and the lava tree is left standing proud.

Mauna Ulu built itself up to a height of 120m above its surroundings. This was done by a series of lava flows like that below.

Chris on a lava flow, Mauna Ulu
Chris on a lava flow, Mauna Ulu

Put a lot of these together and you end up with a lava shield.

The Mauna Ulu lava shield with a perched lava pond
The Mauna Ulu lava shield with a perched lava pond

From the lookout over Mauna Ulu you can see, on a good day, Pu’u ‘O’o where most of todays activity is.

Pu'u 'O'o and Kane nui o Hamo from near Manua Ulu
Pu'u 'O'o and Kane nui o Hamo from near Mauna Ulu. The sharp peak in the distance is part of Pu'u 'O'o. The green hill with fumarolic activity is Kane nui o Hamo. Mauna Ulu is just out of the picture to the right.

There is much, much, more to the geology of Hawaii than I have given here but I hope I have given a taster of what can be seen. I’m disappointed that there was no flowing lava to look at but what I saw was very interesting. I suspect I will have to come back again!

A very good map and pamphlet about the geology of Kilauea can be downloaded from HERE.

Our Bush Trip

On Friday 22nd January Chris and I set off from Perth, accompanied by John and Julie, to sample what geology in the bush is like. It was almost like old times for John and Julie were fellow (sorry Julie!) members of my geology class at Aberdeen University, many years ago.

Friday

We were to be away for four days and three nights, and, this being Australia, the first day was devoted to getting the miles done. As we took to the dirt roads we began to see kangaroos hopping across and emus running in front of us, too daft to get off the road. We were headed for a place called Sandstone and accommodation in a donga. Dongas are semi-mobile accommodation, designed for use in the bush. Really they are shipping containers with bathroom plumbing and an air conditioner. Ours was the noisiest air conditioner in Western Australia.

The bar and our donga
The bar and our donga

Actually the place was quite good as there was a bar, grass and a small swimming pool. The proprietrix took in damaged kangaroos from the Conservation Department and looked after them till they were able to be sent on to zoos etc. They were no longer wild so could not be released into the bush.

Kangaroo and joey at Sandstone
Kangaroo and joey at Sandstone

Kangaroo and joey at Sandstone
Kangaroo and joey at Sandstone

We had our evening meal at the Sandstone National Hotel, which was full of prospectors, geologists and drinkers. (Many of them were all three.)

Saturday

Our main purpose on Saturday was to look at John’s astrobleme. But we looked at several things along the way. The first was London Bridge, a natural arch in weathered basalt.

London Bridge, Sandstone, Western Australia
London Bridge, Sandstone, Western Australia

There seems to be quite a lot of these natural bridges – I saw several as we drove along but this one is close to a town and has a road leading to it. They form when erosion forms a ridge. The uppermost layer is often lateritic and is therefore harder than the weathered rock underneath, so erosion breaks through the subsoil first.

London Bridge, Sandstone, Western Australia
London Bridge, Sandstone, Western Australia

From there we headed to the Barrambie layered intrusion. This is comparable in size to the Bushveld in South Africa, but has had a much more active geological history. Despite decades of search no one has found a viable platinum mine but vanadium is mined as well as iron ore.

John took us to an ilmenite – magnetite cumulate.

Ilmenite - magnetite cumulate in the Barrambie layered intrusion
Ilmenite - magnetite cumulate in the Barrambie layered intrusion

And to prove that magnetite was present we used a magnet, dropped onto the soil covered with dirt and picked up.

The clean magnet
The clean magnet

The magnet after being dropped in the dirt
The magnet after being dropped in the dirt

It is not easy to clean the magnet after this – magnets and magnetite have a strong affinity!

Then we were off to see the Yarrabubba astrobleme. Time has not been kind to this meteor impact. Any crater there was has long been eroded away – all we have left is what happens deep below the impact. It was first noticed several decades ago when a Survey geologist noted some shocked quartzs in thin sections of rocks collected in the area.

Nothing was done with this until John was working on other impact structures and came across the reference. The felsic Barlinga granophyre and the nearby potassic Yarrabubba granite are rather unusual for this part of WA. Geophysical evidence shows that area have been demagnetised.

On the Barlangi Granophyre
On the Barlangi Granophyre

Field work showed that the Barlangi granophyre had been injected horizontally and forcibly into the country rocks.

Climbing Barlangi rock
Climbing Barlangi rock

Xenoliths of country rock can be seen.

Granite xenolith in the granophyre
Granite xenolith in the granophyre

And shatter cones were seen.

Shatter cones at Yarrabubba
Shatter cones at Yarrabubba

Pseudotachylite veining can also be seen.

Pseudotachylite veining at Yarrabubba
Pseudotachylite veining at Yarrabubba

The Barlinga granophyre was probably formed instantaneously when the meteorite impacted and injected itself higgledy-piggledy into its surroundings, making things most uncomfortable for all the minerals down there. In particular quartz had to equilibrate quickly.

Quartz with feldspar rim, Yarrabubba
Quartz with feldspar rim, Yarrabubba

After this we set off for Cue, another small town. And on this portion of the trip we found ourselves to be very lucky. After driving for over a hundred kilometres on dirt roads with no other traffic, we turned onto the Great North Highway just north of Cue – and almost immediately had a puncture. It turned out that our vehicle did not have a wheel brace and we could not change the tyre until another vehicle came to our aid. If the puncture had happened while we were on the dirt roads we would have been in some difficulty.

Sunday

We left “The Queen of the Murchison” B&B in Cue for Walga rock and found it covered in puddles. There had been rain overnight and, later, we found that some of the rivers were actually flowing!

On Walga Rock - a granite
On Walga Rock - a granite

Round the edges of these granites is a good place to look for water.

waterhole at the edge of Walga Rock
Waterhole at the edge of Walga Rock

We then went on to Jokers Tunnel – an unsuccessful gold mining venture. A tunnel, about a hundred metres long, was driven through a ridge, hoping to find some gold. Nothing was found . And the tunnel still survives. It was driven using hammers and chisels and probably without explosives.

Jokers Tunnel
Jokers Tunnel - and we did not see any snakes!

The entrance to the tunnel - and you can see the exit too!
The entrance to the tunnel - and you can see the exit too!

Unweathered rock in the tunnel
Unweathered rock in the tunnel

Bats in the tunnel
Bats in the tunnel

Wetas in the tunnel
Wetas in the tunnel

Chris in the tunnel with bats (and wetas)
Chris in the tunnel with bats (and wetas)

There are countless reasons for this sort of thing not happening in the UK, but it was fun and no bats (or wetas) were harmed.

Monday

We overnighted in Mingenew and set off for the Coalseam Conservation Park, where the first coal in WA was found. It is Permian and is pretty poor stuff and was never mined seriously. Coals of similar age are mined near Collie to the south of Perth.

Part of the Permian succession, Coalseam Park
Part of the Permian succession, Coalseam Park

Parts of the succession are fossiliferous.

We then went to Cervantes, on the coast, to look at Lake Thetis which has stromatolites – or thrombolites if you listen to the experts.

Stromatolite (or thrombolite) at Lake Thetis, Cervantes, Western Australia
Stromatolite (or thrombolite) at Lake Thetis, Cervantes, Western Australia

Stromatolites (or thrombolites) at Lake Thetis, Cervantes, Western Australia
Stromatolites (or thrombolites) at Lake Thetis, Cervantes, Western Australia

And lastly, for a final treat we visited The Pinnacles which are spectacular structures of controversial origin. See HERE.

The Pinnacles
The Pinnacles

The Pinnacles
The Pinnacles

It does look rather like a temple for penis worshippers, but even so it was a nice place to end our tour of the bush.

I am filled with admiration for the geologists of Western Australia who have done so much with little outcrop and even less fresh rock. And they are working in extremely harsh environments of heat, drought and flies. Surviving in the bush is a full time occupation – doing geology as well is remarkable.

Alice to Adelaide

On Tuesday 7th December we flew from Cairns to Alice Springs. The flight took us almost two and a half hours and, after leaving the Atherton Tableland behind us, we saw no other settlements. The only signs of civilisation were long, straight, empty roads disappearing into the distance.

At Alice we transferred to a Backpackers hostel, had a wander round the town, including crossing the Todd River, and had supper. We had to be at the roadside, ready to go, at 5! We had booked an overland trek to Adelaide with Australian Adventure Tours and we were going to see “The Centre”.

Wednesday

And at 5 we were picked up by “Doc” our group leader, guide, cook, expert on Aborigines, raconteur and “animateur”. We toured round various other hostel and hotels till we had got all our fellow travellers. Then we set off for Uluru via King’s Canyon.

Our bus and trailer
Our bus and trailer

Despite looking close together on any map of Australia, Alice and Uluru are over 200 miles apart. And if you go via Kings Canyon, the journey is over 500 miles. And most of the way is through featureless scrub. So there was a lot of sitting in the bus, dozing, waking with a start and finding the scenery had not changed.

Tame emu at our refuelling stop
Tame emu at our refuelling stop

Stops were for refuelling – you need to know how far to the next petrol station – and toilet stops. And lunch stops. At various places you would find barbecue facilities – places for food preparation and gas powered barbecues. And here Doc’s expertise would come into play. He would have us organised cutting up salad, cooking, slicing etc. And afterwards doing the washing up.

Doc (on the right) shows us how to cook lunch
Doc (on the right) shows us how to cook lunch

At King’s Canyon Chris walked along the canyon while I went up to the canyon rim. The temperature was in the high 30’s and early 40’s, the trail was steep, so we all suffered. Plenty of drinking water and sunscreen were essential.

King's canyon - the climb to the rim
King's canyon - the climb to the rim

King's Canyon
King's Canyon

King's Canyon
King's Canyon

Gum tree on the rim of King's Canyon
Gum tree on the rim of King's Canyon

The rocks are Sandstones and Shales 350 million years old and show many signs of shallow water deposition. And there are even desert dunes. I think a creationist had preceded us up the trail – all the dates on the explanatory signs had been scratched out! The views are wonderful with the strong reds of the rocks, the deep blue of the sky and the green of the vegetation.

Geological information sign, corrected by creationist; ie information deleted, nothing added
Geological information sign, corrected by creationist; ie information deleted, nothing added

Current bedding in King's Canyon
Current bedding in King's Canyon

Near the top of the rim, King's Canyon
Near the top of the rim, King's Canyon

Generally it would be the grey and yellow of the vegetation, but we were continually reminded that this had been an unusually wet season with lots of rain. Doc told us that to be called a local in Alice Springs you needed to have seen the Todd flow three times. It had taken him three and a half years to see this. But this year it had flowed 8 times!

While on the top of the canyon we had heard thunder and while driving back to the Uluru main road we crossed several water splashes. Rain is so infrequent that rather than build bridges over creeks, they let the creek flow over the road. This is fine if the water is shallow but sometimes a road can be closed for days.

The road to King's Canyon
The road to King's Canyon

Did I mention the red earth?
Did I mention the red earth?

We got back on the Uluru road and got to our camp in time to see a Uluru sunset and also KataTjuta (previously the Olgas, looking very like Homer Simpson). Uluru used to be Ayer’s Rock.

Kata Tjuta, the Olgas or Homer Simpson
Kata Tjuta, the Olgas or Homer Simpson. Homer is lying down with his head on the right.

Sunset near Uluru
Sunset near Uluru

Our camp was a permanent one with a kitchen and dining hut and tent-like huts with bunks. But many people slept outside looking at the stars which are amazingly bright. You get all the bright stars which you can see in town but, in addition a host of less bright one filling the spaces in between.

Thursday

We were up before 4 in order to see our Uluru sunrise. This was rather impressive as some of my photos may show.

Sunrise at Uluru
Sunrise at Uluru

The sky at sunrise, Uluru
The sky at sunrise, Uluru

Sunrise at Uluru
Sunrise at Uluru

Sunrise at Uluru
Sunrise at Uluru

Then we went for a walk around the base of the rock. This is mainly a coarse sandstone. Various parts are sacred to the local people and therefore should not be photographed. I think all my photos are legitimate, but it is very difficult to be sure. Much of the culture of the locals seems to be explanations of how the rocks look as they do.

Wild flowers at Uluru
Wild flowers at Uluru

Erosion of Uluru; or Darth Vader
Erosion of Uluru; or Darth Vader

Detail of Uluru
Detail of Uluru

Waterhole at the base of Uluru
Waterhole at the base of Uluru

Uluru erosion or a crocodile
Uluru erosion or a crocodile

The way to the top - not encouraged
The way to the top - not encouraged. The Australian Government gave Uluru back to the aborigines on the condition that people could climb it. But the Aborigines do their best to discourage you.

Uluru in the daytime
Uluru in the daytime

Then we went to Kata Tjuta to walk into Walpa Gorge. The rock here is a very coarse, polymictic conglomerate. I thought I was back at Dunottar Castle in the Old Red Sandstone!

Walking into Kata Tjuta
Walking into Kata Tjuta

Walking into Kata Tjuta
Walking into Kata Tjuta

In Kata Tjuta
In Kata Tjuta

In Kata Tjuta
In Kata Tjuta

View of Kata Tjuta
View of Kata Tjuta

Back to the camp for lunch and rest. Aborigine Culture Centre and walk round another part of the rock where we got to look at various caves and waterholes.

Walking to the base of Uluru
Walking to the base of Uluru. The black bit is where water runs when it is raining.

Waterhole at the base of Uluru
Waterhole at the base of Uluru

And finally our final Uluru sunset.

Uluru Sunset I
Uluru Sunset I

Uluru Sunset II
Uluru Sunset II

Uluru Sunset III
Uluru Sunset III

Friday

We travelled to Coober Pedy, a distance of about 460 miles, passing nothing of any great interest – mile and miles of bugger all – as one of our companions described it.

But Coober Pedy was worth looking at. It is the centre of opal mining and if it were not for opals it would not exist. It is bleak, dry and hot. So if you can, you live underground where temperatures stay stable at about 25 degrees. Our bunkhouse was underground and very comfortable too.

Underground house, Coober Pedy
Underground house, Coober Pedy

We were taken round an old mine which had an underground house at an upper level. And which happened to have an opal selling shop attached. Christine succumbed to an opalised belemnite pendant. And there were various other temptations which we managed to reject.

In an opal mine
In an opal mine. Big brother is watching!

Opal in the rock
Opal in the rock. This is colourless opal and hence valueless.

Polished opal in the shop
Polished opal in the shop. Note the price!

Opalised belemnites fossils
Opalised belemnites fossils

Chris's opalised belemnite pendant
Chris's opalised belemnite pendant

Our underground bunkhouse
Our underground bunkhouse

Walking over the rooftops, Coober Pedy
Walking over the rooftops, Coober Pedy. The "dustbins" are ventilation for underground houses.

Saturday

We travelled to Quorn in the Flinders Range – a journey of 400 miles. And we did pass some things of interest. I was able to photograph a road train in all its glory – usually they just flash past, making the bus rock. And we walked down to Lake Hart, a salt lake. And a T-junction in the middle of nowhere.

A road train
A road train

A road train
A road train

On Lake Hart
On Lake Hart

A road junction
A road junction

Quorn is a town of faded splendour which used to be on the Ghan railway to Alice Springs, but the new Ghan bypasses it. But it is surrounded by the Flinders Range which provides it with a backdrop infinitely more interesting than Coober Pedy

Sunday

This was another early start as we were off to look at Wilpena Pound which is a plunging syncline of Ediacarian age – just before the Cambrian. These rocks contain some very early fossils of which I would see more in the South Australia Museum in Adelaide. But none were observed by me at the Pound.

Wilpena Pound
Wilpena Pound

Charniodiscus arboreus
Charniodiscus arboreus, in South Australian Museum

Dicksonia costata
Dicksonia costata, in South Australia Museum

The area of Wilpena Pound is very scenic with lots of kangaroo and emu.

We made our way back to Quorn by way of Yourambulla Caves where there are lots of aborigine paintings.

Monday

We travelled to Adelaide, a total of 237 miles, but we started by walking up Dutchman’s Stern, a mountain near Quorn. Its name refers to a perceived resemblance to the stern of a Dutch ship, not to anyone’s anatomy. And it had to be an early start as we had to see the sunrise.

Sunrise from Dutchman's Stern
Sunrise from Dutchman's Stern

Sunrise from Dutchman's Stern
Sunrise from Dutchman's Stern

View from the summit of Dutchman's Stern
View from the summit of Dutchman's Stern

The sunrise was quite good and the view from the top was magnificent. And it was a very nice walk. There were lots of kangaroo on the lower slopes.

 Spot the kangaroos!
Spot the kangaroos!

The drive down to Adelaide was in strong contrast to our journeys along the Stuart Highway. There were farms everywhere and we were never very far from a village. And the Adelaide suburbs stretch a long way north.

And so, very soon, we were saying goodbye to our travelling companions and settling in to our Hotel in Adelaide. Together we had travelled 3000km – not bad for six days!

 

Naxos

The reason, or perhaps the excuse, for all this jaunting round Eastern Europe and Greece was WEGA’s excursion to Naxos. I was the secretary of WEGA (the West of England group of the Geologists’ Association) for several years and helped persuade Doug Robinson, a distinguished academic in Bristol University’s Earth Sciences Department, and now Chairman of WEGA, that he wanted to lead this excursion. Actually this was rather an easy task as he takes 4th year students to Naxos every September and he arrived a week early to look after us more aged geologists.

Doug explains the subtleties of a granite outcrop
Doug explains the subtleties of a granite outcrop - the internal structures formed in a squidgy, semi-molten mass, solidifying in a region under directional pressure - ductile structures. Note Doug's expressive hand movements - essential to explain what is going on!

I won’t attempt to give a day by day account of our excursion as, unfortunately, my notes are extremely rudimentary. (They always are!). Instead I will try to give an outline of Naxos’s geological history.

Africa is heading north and is plunging under Crete and the islands of the Aegean. Most of the Aegean islands are made of sea floor sediments which have been taken down to great depths and then brought back up again. Naxos is different. It is a bit of continental crust which has been taken down to great depths and brought back up again. So they have been very effectively cooked and are therefore metamorphic rocks. The great depths are probably 30 km or more and all this happened, as far as geologists are concerned, very recently – the oldest rocks seen on the island are 30 million years old and most are younger. The rocks may have been formed before this but the “cooking” has transformed them into new rocks. We in the UK are used to seeing metamorphics which are more than 600 million years old, so seeing ones which are as young as this is, in itself, very interesting.

Marble and schist showing folding
Marble and schist showing folding

The rocks have not only been heated, but also folded in a very extreme way. One of the characteristic rocks of Naxos is marble. Many of the Classical Greek statues are carved from Naxos marble and the stuff used for those is extremely pure – 100% calcium carbonate recrystallised into large (1cm) crystals. The marble seen above is rather impure so you can see the folding. The pure stuff is similarly folded but the internal structure is impossible to see.

The temperature/pressure regime to which the rocks have been taken is not an unusual one. It has been described in many places, not least in the North East of Scotland, just north of the Highland Boundary Fault. There it was described by George Barrow and hence it is known as Barrovian Metamorphism. The characteristic rock in Scotland is pelite – a posh term for a rather non-descript  rock containing quartz, feldspar and clay minerals, probably formed in seas not far from eroding mountains. When this is subjected to Barrovian metamorphism the mineral composition of the rock progressively changes as the temperatures and pressures increase. The sequence of characteristic minerals with increasing grade is chlorite, biotite, garnet, staurolite, kyanite and sillimanite. In Naxos we do not find staurolite but the rest of the sequence can be found. Accompanying this change in mineral composition there is change in the rock type. We move from schist to gneiss to, eventually, migmatite where the rock starts to melt to form granite. And we have large granite masses on the island.

There are pelites on Naxos – quite a lot of them – formed from eroded mountains, but there are also huge amounts of marble which presumably formed in shallow seas with little sediment input. And there is an amphibolite – metamorphosed igneous rock – and some exotics which we will come to later. Even without the exotics we have an unlikely environment providing our raw material for metamorphism to cook.

Mt. Zas, 1001m, Naxos
Mt. Zas, 1001m, Naxos. A huge mass of marble with bands of pelitic schist - the vegetated bits on the mid-upper left.

Migmatite, Naxos
Migmatite, Naxos. Shows the white neosome (new rock) in the upper part and the darker paleosome in the lower. The neosome has been melted out of the paleosome and squeezed to intrude its surroundings. Note the dark fragment (upper centre) bent to the left by the movement of the neosome. The neosome is virtually a granite.

Kyanite being pseudomorphed by sillimanite, Naxos
Kyanite being pseudomorphed by sillimanite, Naxos. As the deeply buried rock rises to the surface due to erosion and tectonic forces, the kyanite becomes unstable and changes into sillimanite, which has the same composition but different structure.

Aluminium phase diagram and Naxos
The route through Temperature and Pressure of the Naxos rocks

 

Kyanite, sillimanite and andalusite have the same composition – aluminium silicate – but are stable at different temperatures and pressures. When a rock containing one of these minerals has its environment changed the aluminium silicate will change to the stable form. In Naxos, as the pressure drops the stability field changes from kyanite to that of sillimanite. Why has only a proportion of the kyanite been changed ? Because the change requires an energy input and this is only available in small quantities as the pressure and temperature drop. For the same reasons andalusite does not form.

And now for the exotics. The following pictures show, in one, a pod of pure sillimanite, and the other an emery mine. Sillimanite is aluminium silicate and as a starting material, before metamorphism, it must have been kaolin, and this would require a long period of surface weathering. And emery is aluminium oxide, requiring a starting material of bauxite – again a long period of surface weathering is required. How this fits in with Naxos’s pelites – submarine, nearby coastline – its marbles – shallow seas, no sedimentary input – its igneous rocks – crustal instability – is, for me, a mystery.

Sillimanite pod
Sillimanite pod

 

Emery mine
Emery mine

There is much more to the geology of Naxos but this post is quite long enough. If you need to know more you will need to go on Doug Robinson’s 4th year excursion, or perhaps, ask Doug.

 

Santorini

Our visit to Santorini started with a catamaran ferry from Iraklion. Our bus from Chania got us there in lots of time and soon we were on board. It is rather like a very wide airliner. There is no deck to get onto so you only see the passing islands through the windows. Your luggage gets a better view as it is stored on the rear deck in the shelter of the passenger accommodation. On a busy route like Iraklion – Santorini there is an almighty scramble to get your luggage when you dock.

On Santorini we caught the local bus service to our hotel in Imerovigili. We had been told that our hotel was on the Main Road but it was nowhere to be seen on the main road through the village. Enquiries at a shop told us where to go and we found it on a little lane, too narrow for cars. We were later to find that this was not only the Main Road of Imerovigili but also of the island.

The hotel was on the edge of the caldera with wonderful views. It was partially dug into the tuffs of the volcano. Ours was a small suite – bathroom, bedroom, hallway – but next door was one of 150 square metres, complete with 3 double bedrooms, huge lounge, plunge pool bath and several normal bathrooms. But we all got to share the sitting out area.

Chris in front of our cave, Santorini
Chris in front of our cave, Santorini

Breakfast was served up at road level and you could have your fresh orange juice as you look over the caldera.

Breakfast Corner, Santorini
Breakfast Corner, Santorini

But enough of the hotel. After settling in we caught the bus into Fira, the island’s capitol. It is a shoppers paradise. Santorini gets many normal tourists, but also a huge number of cruise passengers. Often you will find three or more vast cruise ships anchored in the caldera. And many of these people have lots of money. It is the duty of Santorinians to help them to get rid of it. There is a more than adequate  number of jewellery shops and establishments for other things you didn’t know you needed.

Shop on Santorini
Shop on Santorini

We had arrived at the New Port which is some distance from Fira. But the Old Port is just below Fira and is reached by a stairway of 580 steps or by a cable car. You do not need to walk up the steps; you can sit on a donkey. I reckon the bus from the New Port is preferable.

Donkey Jam on the steps from the Old Port
Donkey Jam on the steps from the Old Port

On our wandering in Fira we discovered the Main Road. It is what must be an ancient path along the lip of the Caldera. It winds too and fro and goes up and down steps and for most of its length is lined with shops, hotels, houses and restaurants. We decided to see if it went to Imerovigili – it does! And there are wonderful views to be seen all along it. And it, so I am told, goes all the way to Ia at the far end of the island. You can’t drive along it but you could take a donkey along it.

The Skaros, Santorini
The Skaros, Santorini, seen from the Main Road

The next day we joined a tour of the volcano. We travelled by boat to the island of Kea Kameni. 500 years ago this island did not exist. It is the newest land in Europe. The last eruption was in 1950. Our guide was enthusiastic and new a little about geology. But he showed us the various craters and, most effectively, demonstrated high heat flow by scraping up some dirt near a fumarole and dropping it into our hands – it was hot!

Walking on Nea Kameni
Walking on Nea Kameni

Perhaps the best, short, means of describing the geology of the islands is to show the brochure you get when you land on Nea Kameni. Note that the brochure is only describing Nea and Palea Kameni, not Santorini as a whole.

Geological History of Nea and Palea Kameni
Geological History of Nea and Palea Kameni

After leaving Nea Kameni we went to Palea Kameni where the adventurous among us went for a swim in the iron bearing hot springs. We could not land but the more adventurous of us could swim to them. Of course this included Chris.

Swimming to the hot springs, Palea Kameni
Swimming to the hot springs, Palea Kameni

After lunch on Therissia, which is the island on the other side of the caldera from Santorini, and where we collected some pumice, we went to Ia to watch the sunset and to engage in the retail experience. On the way we saw some of that days tally of cruise ships. Below is a photo of them taken from Nea Kameni.

Cruise liners at Santorini

Cruise liners at Santorini, from Nea Kameni

I also took several pictures of the caldera which can be seen below. At the New Port you can see some Tertiary schists, but the rest of the caldera sides are tuffs and volcanic ash of very varied ages in the Tertiary and Quaternary. The white layer at the top is the eruption of 1600BC.

Fira overlooks the caldera
Fira overlooks the caldera. You can see 1600 BC layer on the right.

Imerovigli and the Skaros from the sea
Imerovigli and the Skaros from the sea

Therissia from our hotel, showing the 1600 BC layer of pumice
Therissia from our hotel, showing the 1600 BC layer of pumice

Ia is a village which was rebuilt after an earthquake in the 1950’s in the original style. The main road is the original donkey trail and cars are not allowed into the main part of the village. It is determinedly picturesque.

Ia, Santorini
Ia, Santorini

But we, and every soul on Santorini with a camera, was there for the Sunset. I show one below. Googling “Sunset Santorini” will probably get a million more.

Sunset, Ia, Santorini
Sunset, Ia, Santorini

Like starlings, photographers gather for the Ia sunset
Like starlings, photographers gather for the Ia sunset

And finally I must mention the Archaeological Museum of Thira which has a magnificent collection of pots and lots of other stuff from the age of Minos.

Pots in the Archaelogical Museum of Thira
Pots in the Archaelogical Museum of Thira

Then after three days on Santorini we set off for Amorgos.

Meteora

The train from Thessaloniki to Kalambaka takes about 3 hours and is, at times, fast. We reached 100mph at times. But there are lots of stops and slow bits. You go on the line to Athens as far as Palaeofarsalos, where the train starts going backwards, along a branch line, to Kalambaka, passing through Karditsa and Trikala. Because it was the weekend we could only buy second class tickets but could sit anywhere on the train. We got on early so were rather comfortably ensconced in first.

When we got to Kalambaka it was dark and rather difficult to find our B&B. A taxi driver refused the fare as it was too close, but he did point out the way. We found the place and found we had a comfortable room filled with old furniture and very poor lighting. We dumped the stuff and went off to eat. Lady B&B suggested a restaurant on the main street and the place was well worth going to. There was even a poor caged parrot whistling at all the customers.

But looming out of the gloom like giant elephants were the rock pinnacles of Meteora. They are too big to be adequately floodlit but you could sense their presence just beyond your ken.

Some of the Meteora pinnacles from our B&B
Some of the Meteora pinnacles from our B&B

Next morning we agreed to share a taxi with a young Japanese woman whose command of English was on a par with our knowledge of Greek. Her name was Eme. The taxi took us to the largest monastery, Grand Meteora.

Grand Meteora, from the road
Grand Meteora, from the road

The pinnacles are made up of sandstone, ranging in grain size from coarse to conglomeratic, with a tendency for the coarser types to be the more abundant. Contained clasts can be up to about a metre in diameter. They are all rounded to some extent. They remind me of the Old Red Sandstone near Stonehaven, except that the rocks are greyish yellow to brown in colour, not red. The sources I have found suggest an Early Tertiary age for them. So the rock type is not particularly unusual.

But the geomorphology most certainly is. My interpretation, based on a day in the area, is that there is a large fault running along the Kalambaka valley. The rocks on the side opposite Meteora look different from that of the rock pinnacles. Behind the pinnacles is a plateau. So we are at the edge of a massive sandstone block with various small faults breaking the edge of the sandstone into small blocks. Erosion has worked along these faults so that now only the cores of the blocks remain. Why are the valleys so steep – sided? Probably because the sandstone mass was being uplifted at a rate which did not allow the streams to do other than cut down. It was taking all their energy to erode downwards, never mind going from side to side. The result was the pinnacles we see today. And on these some mad monks built monasteries.

The typical way to get to a monastery is to go up a valley from the main valley until you get to the level of the plateau. As you go up, other valleys lead off at right angles. At the top, you walk along the edge of this secondary valley till you get to a monastery. You then have to descend to the bottom of the valley and then up some 150 steep steps to the monastery. At the monastery you look down on Kalambaka grateful that you did not have to climb up from that side!

In the picture above we see Grand Meteora Monastery with the secondary valley between us and it. Beyond the monastery is a huge drop to the Kalambaka valley.

Going down to the monastery entrance
Going down to the monastery entrance

Looking along the secondary valley to Varlaam Monastery
Looking along the secondary valley to Varlaam Monastery - note the bridge to the entrance

Despite their unusual position a monastery is a monastery and these have all the usual – libraries, hospitals, treasuries, chapels etc. What they do not have is space for a graveyard so bones of dead monks are kept in a storeroom.

Ossuary in Grand Meteora
Ossuary in Grand Meteora

The monks are not keen on photography inside their buildings and they are not at all keen on women. I was able to go round in shorts, but women had to put on wrap-round skirts and shawls if their shoulders were showing.

After a look at their buildings and their ancient manuscripts – some going back about a thousand years we set off for the next monastery – Verlaam. We were walking from now on so we made sure we carried a bottle of water with us. On the way we saw Rousanou Monastery.

Rousanou Monastery beyond Verlaam
Rousanou Monastery beyond Verlaam

Verlaam – named after its founding monk – is smaller than Grand Meteora, but equally difficult to enter.

The entrance to Varlaam Monastery
The entrance to Varlaam Monastery

Varlaam has all the usual monastery stuff, especially paintings of Orthodox saints martyred by the Ottomans, and old manuscripts with wonderful handwriting, but the most approachable was a 21,000 litre barrel which, I suspect, is no longer waterproof. What monks would do with a barrel this size I do not know. Surely not wine?

21,000 litre barrel
21,000 litre barrel

We then set off on a long hike (5km) to the Aghia Tridia and Saint Stephen Monasteries topping up our water supplies before we set off. On the way there were various viewpoints from which to take photographs – see below!

On the map following, after inspecting the map, click on “View larger map” to see additional information regarding the positions of the monasteries.

Rousanou Monastry
Rousanou Monastry

Rousanou Monastery with St Nickolas beyond
Rousanou Monastery with St Nickolas beyond

Four Monasteries - from the left, St Nickolas, Rousanou, Grand Meteora, Verlaam
Four Monasteries - from the left, St Nickolas, Rousanou, Grand Meteora, Verlaam

When we got to Aghia Tridia (Holy Trinity) we noted that their was a path to the village which started at the low point of the path to the monastery, so we decided to do that last, and pressed on to St Stephens.

Aghia Tridia
Aghia Tridia

And when we got to St Stephen’s we discovered that it was about to close for a two hour lunch break.

St Stephen's Monastery
St Stephen's Monastery

So back to Aghia Tridia where we discovered that hunger for lunch had triumphed over hunger for monastic knowledge. So we took the footpath down – very steep, very hot and very long.

Meteora Cliff
Meteora Cliff

When we got to the bottom we had our lunch and decided we needed a rest. Next morning we found that we had to take an early train to get to Athens on time, so we could not get back up to Aghia Tridia as we had hoped.

But we were certainly impressed by what we had seen – World Class Scenery capped by World Class Monasteries!