Hallucigenia

In the last thirty years there has been an explosion of fossil discoveries in China. These have added significantly, perhaps even revolutionized, much of our earlier knowledge of some geological eras. I knew that museums in China have wonderful collections of fossil dinosaurs. I was surprised to find that the new discoveries span a much longer history. The Cambrian, which started about 540 million years ago, and lasted for over 50 million years, is part of this. Our earliest knowledge of the biota of the Cambrian came from the Burgess Shale, found in Canada in 1909. The slow fragmentation of the large super-continent of Pannotia, its warm coastal seas, and the complete lack of land plants still supported an immense variety of aquatic life. One of these animals was the Hallucigenia whose fossil from the Chengjiang shales I saw in the natural history museum in Shanghai.

Model of pre-Cambrian animal Hallucigenia

The fossil looks like a crude sketch. It was first described in 1977, when it was reconstructed upside down and front to back. Walking on seven pairs of spiny legs while waving seven tentacles on its back made it something that could be dreamt up on a trip, hence the name Hallucigenia. It turned out that the blob at one end of its body is not its head, but the contents of its guts squeezed out by the clay which buried it. Finally, with electron microscopy, in 2015, a final picture could be created not only of the way it looked, but also how it walked (what a difference good optics makes!). What the animation above does not show is the circle of teeth around the throat, and that is new information which connects it to the family tree of insects. It was once thought that most of the Cambrian animals left no descendants; this may not be true.

Above the rift valley

45 million years ago the continental plate of Africa began tearing into three. About an hour’s drive westwards from Nairobi you get to see the long crack where the Somali plate is separating from the Nubian plate. We took the B3 Escarpment road and stopped at a gap between souvenir shops. It was early in the morning, and sun had not yet burnt the chill out of the air. We stood in the way of the upward rushing air and looked out at that enormous valley, thinking of the grasslands teeming with wildlife, and how in another 45 million years it will be part of the sea separating the continents of Nubia and Somalia.

I looked around at the shops around us. Several sold the usual carvings and paintings. But there were a few which sold sheepskin. I’m sure that this wouldn’t last long in the humidity and warmth of Mumbai. But some of the shops had nice paintings of animals. For that matter, the railing separating us from the long drop to the valley was also painted. We admired them and moved on.

The road drops steeply to the floor of the valley after this, and both of us kept looking out at that enchanting view. On the way back, a few days later, I noticed the distinctive flora of this region: the very tall African candelabra (Euphorbia ammak) also known as the Candelabra spurge. Just before the road climbed steeply I saw a church which looked totally out of place. As I took the photo, The Family noticed a signboard which said that it had been built by Italian prisoners of war during the second world war. That gave me a little handle with which to tease information out of the net. It seems that B3 was built by these same prisoners. The search also led me to a book called No Picnic on Mount Kenya, which is an account by one of the prisoners, Felice Benuzzi, who broke out of his camp to go and climb Mount Kenya. It is quite a read.

I leave you with a superb photo captured by The Family from our car as we made fitful progress through the horrendous traffic on B3 in the evening.

Instant winter

When I booked tickets to Nairobi on a flight which left Mumbai before 6 in the morning, I was looking forward to arriving at 10 AM, with a whole exciting day in front of us. I’d forgotten that, this being an international flight, we would have to be awake half the night. As it was, we finished the formalities quickly and had a very early breakfast in the lounge before boarding. My first priority was to catch up on sleep. When I woke up we were halfway through the flight. The map told me that we were flying over the Carlsberg ridge. This is one of the more active zones on the earth’s crust, the border where the Indian and Somali continental plates are pulling apart. This geological feature is named after the brewery which financed the expedition which discovered the ridge. What a lovely and positive piece of advertisement; I promised to raise a glass of their brew to cheer their commitment to science. I peered across the still sleeping figure of The Family. The sea looked pretty calm.

A little later we were over Africa. A whole new continent! We’d sighted land a little south of Mogadishu. I gazed down at the parallel rows of clouds which you see in the photo above. I’d never seen this kind of weather before. I was to find later that these so-called cloud streets are parallel to the direction of the wind. So the cloud street showed me that a cool wind was blowing in from the sea as Somaliland heated up. The land below us remained brown as we passed over the equator. Another lifetime achievement for us; this was our first time in the southern hemisphere. In an instant we’d passed from summer to winter!

Everything would be new and different (even the style of artwork on the sachets of salt and pepper given by the airline). We peered out of windows eagerly as we landed in Nairobi. The landscape was brown and dry, as it had been as we flew over Somalia and inland to Kenya. “Karibu”, one of security men said in welcome as he showed us which way to go. The Family and I looked at the windows near the immigration queue; zebras and acacia trees, lions and elephants were painted on them. We would see them soon enough. I pulled a jacket over my t-shirt. It was colder than a winter’s day in Mumbai.

The rift where man was born

While planning a visit to the East African savanna, I thought I would read up on how old this landscape was. This led me down an exciting path of discovery through articles which connected geology, weather, and human evolution, and told me about how much more there is to see than just the Big Five. In the featured map you can see a long valley down the center of Ethiopia, ending somewhere a little south of Nairobi. Equally visible is a line of lakes along the border of Uganda and Tanzania. These are the eastern and western East African Rift Valleys.

45 million years ago, soon after India crashed into the still forming Eurasian continent, a massive plume of magma welled up from deep inside the earth near where Djibouti is today. This cracked the continential plate of Africa into three: the present day Arabian plate, and the still separating Somalian and Nubian plates. Signs of this immense geological change are visible in the creation of the Gulf of Aden, and the 30 million years old lava fields and highlands of Eritrea and Ethiopia. In geological time, this is not long before the split between monkeys and apes (hominoids). It is now believed that the geographical changes due to this initial rifting may have cause climate changes that favoured the rise of the hominoids.

The magma plume later created two bubbles below the African plate and pushed up the highlands of Kenya and Ethiopia (clearly visible in the map). About 7-10 million years ago, the heated rocks of the African continental plate began separating out, with the Nubian plate pulling west and the Somalian plate moving eastward. The land between them subsided, and the Walls of Africa rose up 3 to 4 kilometers high. The high walls blocked off wet air from the oceans, changing the climate locally, and converting forests to grasslands. This is also the time at which the split between apes and humans (hominin) took place.

Darwin thought that modern humans had arisen in the grasslands of Africa. The discovery of hominin fossils along the rift valley seemed to agree with this theory. But modern thinking is that the savanna of the rift valley and hominins evolved together as a response to geology and weather. Humans evolved in this land, and then left to settle in far corners of the world. When I go to see the annual migration in the Serengeti, or to look at the dormant volcano called Mount Kilimanjaro, or even to taste the wine grown high in Kenya’s rift valley, I will be a migrant’s child come back to marvel at the homeland that his ancestors left.

Cleopatra’s pool

The hot water of Pamukkale was gathered into indoor pools in antiquity. The story that Cleopatra swam in this pool cannot be verified, although you can now pay to relax in it. She is known to have visited Tarsus and Antioch, far to the east of Hierapolis, and Rome, very far to the west. I think it is unlikely that she took time off from survival politics to come to this place. Most tourists don’t care too much for this story either, and prefer the natural pools on the white cliffs (photo above). They are attracted more by the geothermally heated waters, ie, the geology, than the history.

For good reason. The deep geology of Anatolia is amazing and recent. Just after India, Italy, and Spain collided with the newly forming Eurasian continent and pushed up the Himalayas, Alps, and the Pyrenees, the Tethys seaway was a continuous strip of sea that joined the Mediterranean to the Indian ocean. Between 20 and 10 million years ago, Africa and Arabia pushed north to cut off the Tethys sea.

As a result, the sea bed was pushed above the Eurasian continental plate, forming the Anatolian plateau. The Aral, the Black, and the Caspian seas are the last remnants of Tethys. The closing of the Tethys sea also created the major temperature fluctuations of the last 20 millions years or so, causing huge extinctions, and clearing the way for the rise of modern day mammals and birds. The continuing northward movement of Arabia, and the southwestern movement of the Aegean sea bottom still squeezes Anatolia, making this one of the most geologically active regions on the globe.

This activity not only pushed up the plateau on which ancient Hierapolis stood, but also created the fissures, called faults, which run through it. The raising of the plateau creates a cliff which faces the modern village of Pamukkale, Rain water and snow seep through the crust, are heated underground, and emerge again at various places on the plateau to form these hot springs. The waters are loaded with minerals of various kinds which deposit as the water cools. The flow of water down the cliff has formed these immense terraces of limestone called Travertine.

I’d only seen photos of white Travertine terraces, filled with pools of water. But actually there are various colours to be seen. This is natural, since the water coming out of the earth must have more than just lime in it. These other minerals give the limestone its colour. You can also see in these photos the interesting variety of textures in these deposits. I waited till a little before sunset to take these photos. Then, as the air cooled, The Family and I found our way out of the plateau through the south gate, and came down to the village.

Plutonium in Hierapolis

Passing through the city of the dead, the Necropolis, we would enter Hierapolis through the triple arched northern gate (featured photo), erected in 84 CE, when the town was rebuilt after a major earthquake, to welcome the Roman emperor Domitian. From there a kilometer long path would lead into the city where I really wanted to see the Plutonium.

But between the Necropolis and the gate there was a structure which was probably in danger of collapsing, and was fenced off from tourists. This was the Roman bath, which welcomed travelers to clean themselves after their journey and before entering the city. It is said to have been built in the 2nd century CE, and was converted into a Byzantine basilica a couple of hundred years later. It is interesting that the Romans would oil themselves before a bath, and then would remove the oil with scrapers and water while taking a bath. They picked up the idea of using cakes of animal fat as soap from barbarians. By the time this city was rebuilt, soap would have been common. After walking past the bath/basilica I realized that the fencing could have been prompted by UNESCO, whose listing of this site as a world heritage notes that the biggest conservation concern for Hierapolis is visitors.

Just inside the gate, to our left were the public toilets. The last one which we had seen was in Ephesus. There one had to guess at the structure because the walls had fallen down long ago. This one was fairly intact for a two thousand year old structure. You could see the remnants of the stalls. We’d noticed underground pipes along the road as we walked past the Necropolis. I guess that in the usual Roman fashion, water and sanitation was a major design criterion. The Romans may not have understood the microscopic reasons behind diseases, but they had enough experience to make sure that sanitation was good enough to minimize the chances of outbreaks of diseases. The baths and the toilets, so close to the city gates, were clear signals of their understanding of these principles of health.

The buildings on the other side of the road no longer stood. Some arches columns were still upright, but the rest of the structures had been reduced to foundations. Typically, there would be a market this close to the gate. The more elaborate columns at the back would have been the beginning of the city proper. There was not much to see here, and I walked rapidly through the rest of the long city looking for my target. It turned out to be away from the baths and the travertine cliffs, towards the distance where the theatre stood. I’d already seen several ruined theatres, so I wasn’t planning to walk up to it.

The Plutonium was dedicated to the god of the underworld. It is a grotto near the temple of Apollo (photo above) which emits steam and other gases from the fault beneath the horst of Hierapolis. It is said that the priests of Cybele could approach this opening to the underworld on their bellies, descend part of the way, and often come back alive. There are no priests today, and the whole area was fenced off. The hot springs that flow here are due to rainwater seeping into the faults, and then being forced out. The city is built on top of a geological fault which has slipped by a meter and a half since the late Roman times. Looking at a geological map of the fault zone I realize that the Plutonium was on it. The Romans were right, it was a glimpse into the true underworld. Unfortunately it was closed off.

The Sacred Way

The drive from Miletus to Didyma is short. The distance is about 20 kilometers by today’s roads. We’d started from Kusadasi in the morning, driven through a gap between Mount Mykale (today’s Samsun Dağı) and Mount Thorax to Söke, turned along Mount Mykale to Priene, and then followed the highway across a flat land full of fields to Miletus. Two thousand and eight hundred years ago, this flat landscape between Priene and Miletus was a finger of the Aegean sea. Alluvial deposits from the Meander river (today’s Büyük Menderes) have filled in this sea over millennia, leaving the fingertip of Bafa Gölü as an isolated lake cut off from the Aegean. As a result what was once a peninsula with Miletus on the northern shore and Didyma on the southern, is now just a hilly landscape (featured photo) in the last leg of the drive from Söke to Didyma. How much more difficult would have been Alexander’s campaign against Miletus when he was camped in Priene!

The temple of Apollo in Didyma is ancient. There are writings from the 5th century BCE which describe this as a much older tradition. Equally old is a pilgrimage route between Miletus and this temple. Olivier Rayet discovered part of a paved route which he called the Sacred Way, and hypothesized the remainder of the pilgrimage. Theodor Wiegand later went so far as to identify specific features of the landscape with rituals which are mentioned in texts. Wiegand’s way lies closer to the hill called Akron than today’s road, but runs parallel to it after the lovely bay (photo above) along which modern day town of Mavişehir spreads. The local government has opened a hiking path following this century-old reconstruction.

Modern day reconstructions have used computer models of changing landscapes and reconstructed likely paths based on the segments of road which have been uncovered, and reached drastically different conclusions. The main modern idea is that since the topography of the area changed appreciably over the centuries when the temple was in use, the sacred way was remade several times. In particular, there was never a part of the road which came as close to the coastline as today’s highway. This was partly because the coastline was always in flux, but also because an alternative stable route through a valley was available. Wiegand’s way is then as mythical as flying pigs. But then, why do drivers in this peninsula have to watch out for pigs?

Imagination Valley

We reached Zelve open air museum in the afternoon of a lovely day. The sun was warm, but the air was fresh enough that walking was pleasant. One of our target areas was a set of interconnected chambers cut into the rock, from two stories above the entrance level to a story down. Unfortunately some workers decided to burn plastic trash in this region, and the smoke drove us all away. That’s the smoke you can see in one of the photos in the gallery below.

The day was too pleasant to remain annoyed. We found a nice double tower which had been turned into a house by carving out rooms inside. The windows in the tower were painted in decorative patterns. Apparently this area was inhabited until 1952, when the frequency of rock falls and subsidence increased to the point that the population of these villages were evacuated. The earliest inhabitants probably came here during the centuries of the Arab-Byzantine wars, somewhere between the 7th and 10th centuries CE. A thousand years of human habitation is quite as impressive as the landscape through which we walked. Spring brings flowers and butterflies. I managed to take a few photos of a Painted lady, Vanessa cardui. This is often called the most common butterfly in the world; it is found on all continents except Antarctica. Can you help me with an identification of the flower?

After a break for coffee and ice cream we went on to see the fabulous landscape of the Devrent valley. This is popularly known as Imagination valley because of the interesting shapes that erosion has created. The easily eroded Cemilköy ignimbrite is overlaid by the harder Kizilkaya ignimbrite. This more recent layer was laid down in volcanic activity about 4.3 million years ago. In all the interestingly named shapes that you see below, you can see a thin layer of Kizilkaya icing over the Cemilköy cake.

Camel – Imagination Valley, Cappadocia, Turkey
Two dervishes – Imagination Valley, Cappadocia
Lizard – Imagination Valley, Cappadocia

Three volcanoes

As we came in to land in Kayseri airport, I was surprised to see snow-covered peaks. A quick check told me that the cones of three dormant volcanoes poke out over the 1000 meter high plateau of Cappadocia: Erciyes, Hasan, and Melendiz. What we saw from the bus as we transferred to Göreme was the highest of these: Mount Erciyes, whose peak is at an altitude of 3917 meters. In mid-spring it was still fully covered in snow.

We had views of the peak again the next day (above). The volcano last erupted about 80,000 years ago, but is not supposed to be dead yet. Since Kayseri is only about 25 kilometers from it, you might have to avoid this airport in case of Erciyes becomes active yet. I looked at the smooth white flanks of this peak and wondered about skiing, and then was not very surprised when someone told me about the resorts on the slopes of the mountain. Can you climb to the peak? The answer was not very clear, but I guess you could if you wanted to, but it is not commonly done.

On our last day in Cappadocia we traveled southwards, past Nevşehir. The horizon was then dominated by the two peaks of Mount Hasan (3253 meters high) and Mount Melendiz (2963 meters in altitude). Most of the time I saw them as two distinct peaks close to each other, although they are about 40-50 kilometers apart. Apparently Mount Hasan erupted about 9000 years ago. A painting, which was moved from the neolithic Çatalhöyük to the Museum of Anatolian Civilizations in Ankara, is said to be a representation of this eruption. Some call it the world’s first landscape painting. Ankara and the the World Heritage site of Çatalhöyük are both in our bucket list for future visits to Turkey.

My favourite view of the double volcano came when we looked down at the Valley of Doves which runs between Göreme and Uçhisar. The combination of the fairy chimneys carved below our feet into the landscape and the distant snow-covered peaks rising above the horizon is a sight that encapsulates Cappadocia. I wish I’d come here in better light.

A placid volcano

Our tour of south-west Cappadocia stopped at a bowl inside a mountainous terrain filled with water. It was called Nar Lake. Nar is the word for pomegranate in Turkish, and the name comes from the peaks which rim the crater. I found later that this crater was formed in an explosive volcanic event maybe 12-40 thousand years ago. Standing there, I saw a placid crater lake, perhaps less than a kilometer across, empty roads surrounding it, and sparse signs of human habitation.

No part of the world is really undiscovered or unexplored any longer; we’d arrived here on a guided day tour in any case. Although there was no other car or van nearby, any illusion that there are few tourists was dispelled by three children holding a lamb and a donkey, demanding that we pay to photograph them. Still, there is an air of desolation and silence about the area. The rubble at the edge of the crater looked like burnt cinders. Was this the remnant of the building of the road, or part of the original volcanic geology?

I had been hearing bells ringing ever since I got off the bus, and now, looking down, I saw that they came from sheep which were grazing at the bottom of the crater around the lake. I walked a little along the rock cinders and saw that the rocks continue all the way down. Probably not junk from the road then, I thought. The lake has been studied in detail, and sediments in the lake bed have been analyzed to infer climate changes over the last 14000 years. Special conditions at this lake gives a fine grained picture of a succession of wet and dry climates over the millennia, as well as unusually dry centuries.

I found the place beautiful in its desolation. There was abundant grass in the crater, and some reeds grew in a border around the lake. Pollen deposited in the bottom of the lake throws interesting light on the history of this region. Apparently the land was settled by wheat and fruit farmers in the early Byzantine era, abandoned for several hundred years (7th to 10th century CE) during Arab invasions, as a result of which forests re-established themselves. The land was resettled for the farming of cereals in the Byzantine Golden Age, and has been continuously farmed since then. My unaided eyes saw only the surface of this deep history. Nor did I see the microscopic diatoms, Clipeoparvus anatolicus which have been found only in this lake.