August 12, 2017

Great Orme bronze age mine, Llandudno

I used to visit the Great Orme on holidays in the 1960s. At that time I didn't realise it was limestone. I revisited the Great Orme in 2017. I was also able to visit the copper mines, which were only discovered in 1987.

The ancient copper mines on the Great Orme are located in Carboniferous Limestone formed around 330 million years ago. Their discovery in recent years meant the history of the metal age for Britain had to be rewritten, as it was found that mining of the copper ores began in the early Bronze age around 4000 years ago and continued until around 600 BC. This is earlier than first thought.


The above poster says "Mining on the Great Orme began around 4000 years ago. The earliest mining was open-cast, where the green copper ore malachite was exposed on the surface. Hundreds of tonnes of ore were extracted from these surface workings before the miners eventually had to follow the ore below ground. Bronze Age miners had a variety of tools available to them. Specially chosen stones from the beach would have been used as hammers, and animal bones would have been used as chisels and scrapers. Over 2,500 stone hammers and 35,000 bones have been found at the mine."

Mining recommenced in the late 17th century and continued into the 19th century. The main mining area was near the halfway tram station, where shafts and spoil tips can still be seen. Since their discovery in 1987, mining engineers, cavers and archaeologists have mapped the tunnels of the ancient workings as well large areas of the surface landscape, revealing remnants of bell pits aligned with geological faults.

Today the Great Orme Bronze Age Mine is a tourist attraction. It is located close to the halfway station of the tram. It is a self guided tour, starting with a short film. Then you can explore some of the workings, and find out more about life of the Bronze Age miners.


The miners worked underground for more than 1000 years, reaching depths of 70 m (220 ft) below ground. The tunnels were mostly very narrow, many of them were only big enough for children to work in. For lighting they used animal fat lamps or candles.

Entrance to the underground section that is open to tourists.


Looking at a very small passage that would only have been accessible to children

The basic tools of prehistoric miners, found when the ancient mines were rediscovered in the late 20th century, were stone hammers, animal bones and antler picks. Mining was such hard work that the ore-bearing rock was roughly sorted underground and only the ore was taken to the surface. The waste rock was stored in abandoned passages.

When the rock was not too hard, fires were lit to weaken it. The charcoal remains from these fires have been carbon dated, confirming that the mining took place between 3000 and 4000 years ago.

This is thought to be the largest chamber to exist in an ancient mine



One shaft open to the surface is 145 m deep! It goes down to sea level.

You can see an explanation on how the ore was smelted in kilns reaching 1100 degrees C.

It is amazing to think that the site lay entirely hidden for decades, being covered with spoil. The photo on the left shows the site in 1987.

Currently over 5 miles of tunnels have been found, making this the largest known Bronze Age copper mine in the world.

See and read more on the mine www, greatormemines . There are some good photos, a video and lots of info.

Great Orme, Llandudno, North Wales

As a child I had several holidays in north Wales and each time we would visit the Great Orme at Llandudno. However in those days I had no interest in caves and knew nothing about the geology. The Great Orme is in fact limestone. It is a large outcrop of Carboniferous limestone, approx 365-325 million years old.

Across Llandudno bay is the Little Orme which is also limestone.

Google Earth image of the bay with the Great Orme on the left and Little Orme on the right -

The Great Orme is 3 km long and 2 km wide, and rises to 207 m at the summit. It is protected as an SSSI and a nature reserve. It has important habitats for fauna and flora. It has farmland, also a growing herd of feral Kashmeri goats.


There is a road around the Great Orme. Or you can walk up. Otherwise you can take the cable car or the tram to the summit. I did both. They are run by different companies so you have to pay separately for each, so I did the return journey on the cable car, then did the return journey on the tram. With the tram you have to change trams at the halfway station so that gives an opportunity to go to the Bronze Age mine as it is nearby.


Geological features include the limestone pavement. There are also caves but as far as I can tell, none are particularly 'exciting' and are not easy to get to. Some are connected with the copper mines on the headland. See more on the caves.




The limestone is locally dolomitised. Copper mineralisation and dolomitisation are closely associated with fractures and faults. Hydrothermal fluids passed through the fractures creating veins of copper and other minerals.

Dozens of pits dug by miners -


When I visited the Great Orme as a child in the 1960s, the copper mines hadn't been discovered. They were only found in 1987. So on my next visit in 2017 I was able to visit one. See my next blog on the Great Orme Bronze Age Mine.

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May 31, 2017

Portugal

I've just had a holiday in Portugal but didn't manage to see any caves. And I only saw 1 sign to a show cave, Moeda Cave, that is outside Fatima.

Portugal doesn't have many extensive caves. Most are in the rolling hills between Coimbra and Setubal. We crossed a limestone range between Batalha and Fatima, although I wouldn't have recognised it as limestone if I hadn't been told. Photos taken from the coach window -




A show cave leaflet, Grutas de Mira de Aire , near Fatima-


There is a band of limestone in the Algarve, but I didn't go to this area.

May 18, 2017

Dunhuang Caves exhibition in London

Dunhuang is located at the western end of the Hexi Corridor in Gansu province in China. It is like a small oasis surrounded by mountains and the Gobi desert. The area was established by Emperor Wu of the Han dynasty in 111 BC and was a base for imperial China to manage the Western regions. It became an important trading town on the Silk Road.

The Dunhuang Caves is a cluster of sites that include the Mogao Caves, the West Thousand-Buddha Caves, the Yulin Caves, the East Thousand-Buddha Caves, and the Five-temple Caves. These caves are close to each other and follow the same artistic style, among which the Mogao Caves are the most representative. The caves are all man made.

The Mogao Caves at Dunhuang are a UNESCO World Heritage site. "Situated at a strategic point along the Silk Route, at the crossroads of trade as well as religious, cultural and intellectual influences, the 492 cells and cave sanctuaries in Mogao are famous for their statues and wall paintings, spanning 1,000 years of Buddhist art."

"Carved into the cliffs above the Dachuan River, the Mogao Caves south-east of the Dunhuang oasis, Gansu Province, comprise the largest, most richly endowed, and longest used treasure house of Buddhist art in the world. It was first constructed in 366 AD and represents the great achievement of Buddhist art from the 4th to the 14th century. 492 caves are presently preserved, housing about 45,000 square meters of murals and more than 2,000 painted sculptures."

On 16 May 2017, a month long exhibition on the Sacred Art of the Silk Road: Dunhuang's Buddhist Cave Temples opened in London, at the Prince's School of Traditional Arts. I went to have a look on the first day.

There were a lot of digital posters of the cave paintings, with lots of information as well as a couple of replicas of caves. It was quite a lot to take in!


734 rock cut caves were constructed at Mogao Caves from the 4th to 14th c.  Murals and painted stucco statues still exist in 492 of these caves. Replica statues of the Heavenly King of the North and the South -


There was an explanation of the different types of cave halls - one example

Cave 275 is one of the oldest, 397-439 AD and the main wall shows a large cross-legged Bodhisattva Maitreya seated on a lion throne and holding a preaching mudra.



A calsson is the square roof of the cave, shaped like an upside down 'bucket', with painted patterns such a lotuses, Baoxiang flowers, flying celestials, triple rabbits, rounded dolphins, paired phoenixes or dragon and phoenix in the central square, circled by multi-layer stripes of decorative patterns. It is usually surrounded by a splendid and intricate painting of tents, chaplets and golden bells forming a coherent image of a square canopy. Caisson with triple rabbits inside an 8 petal multi-layered lotus which is surrounded by 8 flying celestials and swirling heavenly flowers, from cave 407 -


'Buddha of the Blazing Light' surrounded by celestial and astronomical deities -


Another mural


There was a walk in replica of Cave 3, which is devoted entirely to Bodhisattva Avalokitesvara


One interesting section was about the pigments used for the murals. These pigments were extracted from natural minerals and were treated by crushing, de-ironing, grinding, rinsing and grading to produce a range of hues and shades. These pigments are pure and rich in colour and are durable as well as being light-fast and resistant to acid and corrosion. Gelantine was used as a binder. Bristle brushes were used to apply the paint.


To make the murals, first sandy mud was mixed with straw to form a paste which was plastered onto the cave wall. Then silty mud was tempered with hemp fibre to form a paste, this was applied onto the previous layer. The mud came from the Dangquan River in front of the Mogao Caves. The silty mud layer was then whitewashed with kaolin, lime or gypsum. The surface was then ready for painting.

Freehand sketches were drawn onto sections of the wall, using a brush and a light earth-red pigment. Images were then added and scaled up. Next, the stencilling - outlines of the full scale images were drawn with ink on paper and pricked with holes. A fabric pouch holding coloured powder was  pounced over the holes. The powder coming through the pouch would penetrate the holes in the paper and leave fine dotted lines on the wall. The lines were then inked up to form images using brush and ink. The next process was the colouring. The master artist would draw symbols as colour codes to indicate to the juniors which colours to use.


The deep blue colour comes from lapis lazuli, a metamorphic rock that is mined. It has always been highly regarded and in middle ages was valued the same as gold. It was used for the most precious statues and paintings.

Today the conservation of the Dunhuang Caves comes under the Dunhuang Academy

The next room had a display of calssons.



A mural -

The Thousand-Hand-and-Thousand-Eye Avalokitesvara with Fifty-One Faces at Yulin Cave 3, Western Xia period, 1036-1227.

During the month long exhibition there are short courses on many aspects of the paintings, Silk Road patterns, the alchemy of colour etc, as well as various lectures.

See more on The Prince's School of Traditional Arts and also on Artlyst.

© Liz Price


March 21, 2017

The Azure Window, before and after

My last blog was about the collapse of the Azure Window on the Maltese island of Gozo. A week later I was able to visit the site and see it for myself. I have roughly sketched in where the rock arch was -

And a reminder of how it was -

There was a guard located at the start of the path that used to lead to the arch, he was stopping anyone from going that way.

Now the arch has gone, the piece of rock jutting out from the top of the cliff looks like a face, maybe a gargoyle!

© Liz Price