The Eurasian continent has been thoroughly explored. From Ireland to Kamchatka, there seems little left to discover. Wherever you go, someone has gone before, and left a comment on tripadvisor. People are everywhere, and all geological features are known. We present and explain, but do not discover.
But there are still mysteries. For there are still mountains that few people have ever heard of. Between Ireland and Kamchatka there is one 1000-km long mountain chain where the highest peak, 2400 meters tall, has no name. Anywhere else, this would be a well-known and much-visited mountain range. Here, it is lost. Who could imagine Terra Incognita could still exist in such a well explored continent?
This post is about that mountain range. There are no volcanoes there and volcanism plays only a marginal role, although there is an (in)decent explosion near the end. I hope you don’t mind. This post is all about my curiosity.
The Verkhoyansk mountain range is rugged, remote, and very very cold. To travel there, you may fly to Yakutsk (remember that name from the game Risk?) but it is difficult to get any closer. The main road (the R504 or ‘road of bones’) goes east (cross the Lena river by ferry or ice road – there is no bridge and often the river can’t be crossed and instead helicopters are required) and skirts the mountains – literally so where it is just a narrow track on the side of a cliff! In the winter the Lena river becomes an ice road and can be used to drive north, closer to the real mountain range. You can also fly to the town of Bagatay, and drive west from there. Either case, make sure you have at least two vehicles (always travel in convoy), a working GPS (don’t expect such luxuries as roads), and a guide.
The Verkhoyansk mountain range is located in Yakutia, Russia’s largest province, nowadays known as the Sakha republic. It is the size of India but has a population of less than 1 million. The mountains run from the Arctic ocean to the south, and on the east, in a long arc running partly along the Lena river. The range is named after a settlement 150 km east of the mountains, Verkhoyansk, which itself was named after the river Yana. This town of 1200 people is reportedly the coldest inhabited place on earth! The local temperature record is -67.8 C. It is a good place to raise reindeer, but little else. The cold is dangerous. Temperatures this low cause scar-burns around the mouth. The highest recorded temperature, in rather sharp contrast, is +37.3 C. That is a range of over 100 C!
In 1926, the explorer Sergei Obruchev traveled through the region. In his words: “It was difficult to find a guide even for such a route. The first 150 kilometer, up to the foot of the Verkhoyansk range, lay through an area entirely covered with bogs in which horses were sinking at every kilometre. It was only on the ninth day that we reached the range, an enormous wall separating the coldest portion of the globe from south Yakutsk. At the place where we intersected it, the Verkhoyansk range consists of four parallel chains, of which the main one attains 2500 meters in height and is covered with patches of permanent snow. The southwestern slope of the range facing the Lena and Aldan rivers has an alpine character, due to intense erosion; the slope facing the Yana and Indigirka is gentle, with a number of small chains, and has the aspect of a high plateau. The greatest width of the range at this place is 450 kilometer, and we only reached the Indigirka river at the mouth of its great left-bank tributary, the Elgi river, by the beginning of August.”
A few months later, on the return: “In Oimekon we managed to exchange our horses for supplies, warm clothes, and deer for the return journey. We succeeded in crossing once more the Verkhoyansk range on our way to Yakutsk, but this time in sledges. Our work was seriously handicapped by frosts (from -50 to -60C) and by the necessity of spending the night in tents at such low temperatures. The range is absolutely unpeopled for 600 kilometer of the way. Taryn are another hindrance. Taryn are a peculiar feature of North Siberia. They are formed in winter when the rivers are frozen through to the bottom, and water which cannot make its way under the ice issues through the gravel of the river-banks to the surface of the ice, where it spreads out in a thin layer and freezes. Considerable areas, many tens of square kilometres, are thus frozen over and the valley covered by an ice layer 3-6 meters thick; this ice does not melt during the summer. In summer Taryn present excellent ways for caravans, since they are easier to travel upon than gravel; but in winter the Taryn are great obstacles: they are either congealed and consequently very slippery, or else covered with water into which the deer fear to enter. Not infrequently it happens that several layers of a Taryn are not wholly frozen up, sledges sink into it, and the deer perish. While we were crossing the range three of our sledges were immersed in this way, one my own and two of our guides; but fortunately all was saved. At a temperature of -60 C such adventures are far from being amusing.”
If you think these temperatures are exaggerated, here are the temperature records for this area for 1901. This was a mild year: Verkhoyansk had 72 days without frost, while in 1869 only 37 such days were recorded.
Summer travel can be almost impossible. As a traveler in 1902 wrote “In the summer only Cossacks attempt to travel through with the mail to Verkhoyansk, once each way. The journey, which is made on horseback, is a perilous one, owing to unfordable rivers and dangerous swamps, and the mail carriers are occasionally drowned, or lost in the marshy deserts where they perish of starvation.’ It is easier in winter. The same source: ‘About halfway the Verkhoyansk range is crossed and here vegetation ceases and the country becomes wild in the extreme. Forests of pine, larch and cedar disappear, to give place to rugged peaks and bleak, desolate valleys, strewn with huge boulders, and slippery with frozen streams, which retard progress, for a reindeer on ice is like a cat on walnut-shells.” Few animals can survive the climate. Reindeer do well, but bears are not plenty. The top predator in the area is, without doubt, the mosquito.
This is a hard land. For instance, how do you get water in winter when everything is deeply frozen and permafrost extends a kilometer down? People live along major rivers not only because of transport. In winter, they can be the only source of water, cutting deep through the ice. The Yakut, fairly recent arrivals, have done well. But in the modern era, things are more difficult. The internet comes where roads do not. Young people see that their lives are not like those of other people, they move away for school and work and do not come back. Verkhoyansk has halved in size in 20 years. One day it may cease to exist, one of many ghost towns in Russia.
The mountain range rises in a steep escarpment above the central Yakutian lowland where the Aldan and Lena river flows. The lowland, at around 100 meters altitude, is a typical Siberian landscape, featureless and seemingly never-ending. The flat plains allow the Lena river to widen: the river in places can grow to 8 km wide. The large majority of the water comes from snow melt, and in spring the water flow increases ten fold. This, with the melting ice, can cause enormous flooding. Don’t build too close to the rivers here.
The mountains tower over these plains. They are mostly around 1500 meters high, with peaks over 2 kilometers. The highest peaks are in the central and southern range. To the best of my knowledge, none of the peaks are named: there are too many, often little more than a bump in a long ridge, and of course inaccessible. There are patches of snow even in summer but no glaciers. In fact, not much snow falls in winter. It is too cold and the air contains very little moisture. Most snow falls in autumn and spring when it is freezing but not as cold.
Towards the east side of the mountain range, the ridges become less distinct, less rugged and less tall. The range that started so suddenly now decays into a plateau, which slopes down towards Verkhoyansk, itself only a little over 100 meters altitude. From here, you’ll find an unexpected bonus: a road, which follows the Yana river (at a safe distance) towards Batagay, a town a little larger than Verkhoyansk and with an airport, but less famous because it is not quite as cold. Batagay has a peculiar claims to fame: it is near the Batagaika crater, a kilometer wide and 100 meter deep. If you are now hoping for something volcanic, you will be disappointed. It is a melt structure in the permafrost, currently rapidly growing larger.
Geologically, the Verkhoyansk range consists of a series of folds, each some 20 km wide, which has given rise to parallel ridges. On the west side, a foredeep has developed in which the Lena river has placed itself. Here, the Siberian craton begins, one of the older pieces of continental crust which stretches from the Lena to the Yenisei river. The mountains have developed at the edge of this craton, as part of a crumple zone which stretches 3000 km to the Pacific. The direction of crumple is very obvious from the linear striations in the landscape, here visible in PlanetEarth images from July 2019.
Beyond the Yana floodplain where the towns of Verkhoyansk and Batagay are located, there is a second mountain range, the Chersky mountains (named after a Polish explorer who had been exiled to Siberia), a little higher. These mountains are better known, and more accessible, perhaps because the climate is less extreme. Some of the mountains even have names. (In typical Russian fashion, the highest peak is called ‘Pogeba’ or ‘victory’.) Beyond that there are two more mountain ranges before the Bering Strait is reached. South of there, Kamchatka hangs like an oversized appendix, with its equally oversized volcanoes. It is all a very different world from the plains of western Siberia. Something has happened here.
The Siberian craton
The Siberia craton forms the core of Siberia around which the rest grew. The craton was assembled when at least three different parts came together. The merger seems to have happened in phases at 2.8 and 2 billion years ago, and was complete by 2 billion years. The individual parts are older: the oldest date found for any rock here is 3.3 billion years.
The craton has had a hard life. About 40% of the craton was covered by the Siberian traps eruption at the Permian-Triassic transition, 250 million years ago. This was only half the total eruption: the rest ended up in the neighbouring west Siberian basin. This was one the largest ecological disasters the world has seen, far exceeding the one that ended the dinosaurs.
And this was not its first such eruption. There had already been a flood basalt on the Siberian craton during the Devonian, 370 million years ago. It is called the Yakutsk-Vilyui flood basalt. There may have been one 1 billion years ago as well. Interestingly, both the Yakutsk-Vilyui and Siberian traps flood basalts were followed by a phase of kimberlite eruptions, coming from the deep lithosphere below the craton. Those after the Yakutsk-Vilyui eruption brought up diamonds. Those after the Siberian traps did not.
Flood basalt in cratons have a difficult time to get started. They have to break their way through an extremely thick lithosphere, which is very reluctant to melt. A plume would need to be at 300 C warmer than the usual mantle, and it still would require help from something else that thins the crust, such as rifting or a suture where blocks have come together in the past. (A volatile-rich plume could melt the lithosphere at lower temperatures.) The flood basalt that accompanied the opening of the Atlantic Ocean was in part related to suturing as continental break-up happened along a very similar (but not identical) line to whether the previous ocean had closed. The Devonian flood basalt on the Siberian craton was related to a rifting event. For the Siberian traps we don’t know. The craton was just unlucky to be in the wrong place twice in a row.
The Devonian rifting left us the basin of the Vilyui river, reaching towards an eastern ocean – perhaps a new one. Massive rivers began to bring in sediment from the mountains along the southern and northern edge of the craton, and deposited them on the ocean floor on the east side of the craton. 15 kilometers of sediment formed: this is now known as the Verkhoyansk group. Beyond the ocean was the ancestral North American or Hyperborean plate. The ocean slowly closed over the next 200 million years. When the Siberian traps erupted, this closing was still a distant threat. But by the late Jurassic, 150 million years ago, a continental collision was looming. It happened over the next 50 million years. As usual in such cases, first one or more volcanic arcs arrive, followed by the chasing plate. The arcs attached themselves to the craton. The arriving plate pushed up the sediment that was deposited at the margin of the continent, which folded over and formed mountains. Between the folds and the craton was the foreland basin, almost 1000 kilometers long, on the margin of the Siberian craton. East of the folds was the Kolyma-Olomon terrane which had just arrived. In between remained the folded collection of sediments, volcanic arcs, pillow lavas, black shale – it became quite a complex region.
It sounds all very similar to how Alaska formed, and in fact this land has a very similar history. Kolyma arrived as Alaska was rotating into its position. The various mountain ranges show that new terranes were episodically added, just as happened in Alaska. And most importantly, the newly added land now belongs to the same plate. For the whole area east of the Chersky range is now part of the North American plate. The area from the Verkhoyansk range to the Chersky range is on the Siberian foreland. But east of there, the land is moving with America. It may have been glued to Eurasia, but its loyalty is to a different world. As far as the Earth is concerned, east of here is on the wrong continent. Of course this causes stress and the area shows earthquakes up to M7, although not frequent. Most of those are around the Cherskiy mountains but the Verkhoyansk range had two M6.5 earthquakes in 1927, in its northernmost edge. Not many people will have felt it, and the mountains have been quiet since. Eerily so.
Many of the sediments came from distant mountain chains, pushed up along the edges of the craton. And they brought riches. Many of Russia’s mines are here, extracting gold and minerals. If you are looking for tin, zinc or antimony, look no further than Verkhoyansk. But the riches have a dark side. In the 19th century, when Russia banished dissidents, this is where they were exiled. And in the time of the USSR, much of the work in the mines was done by prisoners: these were the infamous gulags. The Siberian craton had had bad luck, but it also passed this bad luck on.
Udachny and the unlucky diamonds
Not far from the Verdoyansk mountains (by Siberian standards: 500 km or so to the west), on the Siberian craton, is the town of Udachny. It is cold here, 14 km from the arctic circle. Winter lasts 8 months and brings temperatures of -60 C. There is nothing here apart from minerals: the ground water, 300 meter below the surface where the permafrost ends, reportedly contains half the periodic table. However, those were not in minable deposits here. Instead, diamonds are forever and diamonds is what was found here. Udachny is one of 600 kimberlite deposits in Yakutia, of which 150 are believed to contain diamonds although few are economic to exploit. It took a decade for plans to mine the diamonds to become reality. Udachny town was build in the 1960’s. It now hosts some 12,000 people living next to the typical deep, steep hole of the diamond mine, over 600 meters deep. The open-pit mine has closed and a new underground mine has opened. The diamonds are sold through De Beers.
Udachny is unique in one way: it is the only place I know off where diamond mining was helped by nuclear bombs. At least, was tried. It may sound surprising since diamonds are destroyed by heat and nuclear heat is hotter than most. But the bomb was used to help the preliminary building work. Actually, this was an established procedure: over 100 such explosions may have been used across the USSR between 1974 and 1989, twelve of which were in Yakutia. In 1974, a smallish (1.7 kton) nuclear bomb was exploded 100 meters below ground, in order to melt the permafrost, push up the ground and create a water reservoir dam. It was the first of 7 planned explosions, together designed to create a 2 km long, 30 meter high crest which would dam the local creek and create a tailing dump.
It was a disaster. The explosion produced a bank only 14 meters high, far lower than expected, but also released far more nuclear debris into the air than planned for. The debris included caesium strontium, plutonium and even americium. The fallout killed about half a square kilometer of forest, and it took almost 20 years to make the area safe. The town had to be relocated. The hole was plugged in the 1990’s with a 10 meter tall hill of concrete. It all acted as an early model for Chernobyl and its sarcophagus, and was quietly forgotten about. Mining continued in more traditional ways. One may wonder whether the name ‘Udachny’ was an appropriate choice for the town: the word means ‘successful’ or ‘lucky’.
The kimberlite here has an age of 360 million years. It is not entirely clear how the Devonian plume caused this rare type of eruption (if it did). Kimberlite eruptions bring up material from the mantle keel of the craton, typically 100-200 km depth, in a rare type of eruption. They are small, fast, cool, and incredibly deep. There has been no kimberlite eruption in living memory: we have no idea how they happen. But the aftermath brings up a peculiar kind of ‘luck’.
This is the lake mentioned above. It is a mountain lake on the western edge of the mountains, at 340 meters altitude. The climate here is typical for the region: July is balmy, at a mean temperature of 17C, and January is frigid at a mean temperature of -40C leaving the lake deeply frozen. Lake Billiyakh is some 8 by 11 km, and 8 to 20 meters deep. Interestingly, this region was largely ice free during the ice ages. The last glacial advance reaching the lake was 90,000 years ago (the glaciers tended to flow along the nearby river valley instead). This gives a long undisturbed sediment record, and therefore a record of the local climate.
The sediment show that there has been water in the lake over the past 50,000 years, deep into the ice age. While Scandinavia and Canada were deep under the ice, here there was water. The sediment shows the gradual warming (relatively speaking) as the ice age waned. Bushes began to appear 40,000 years ago during a brief (2000 years) warmer interlude in the ice age. 30,000 years ago the area became much drier again as melt water reduced in the colder climate, and the tundra was replaced by grasslands. But 14,000 years the climate became warmer and wetter, the lake deepened again and the wet shrubby tundra re-developed. The modern taiga developed from 7000 years ago. The records agrees well with the temperature record that has been derived from the Greenland ice cores. The main difference is that the Younger Dryas cold snap has no clear counterpart in the Billiyakh sediment, and the warmth of the early holocene took a bit longer to arrive here. However, it is interesting that the glacial cover here was out of phase with that around the Atlantic Ocean. As the American and European glaciers reached their maximum, there was much less glaciation in this area. The earlier peak 90,000 years ago, in contrast, did coincide with extended glaciers here. The cause is probably the air circulation that determined how much Pacific moisture could reach here. Glaciers need snow.
Along the river Yana, east of the Verkhoyansk mountains, is the oldest habitation known in the arctic. Near the delta, evidence for huimanity has been found dating to 32,000 years ago. This is shortly after the warmer interlude found from Billiyakh. It is conceivable that the warmer period allowed the people to spread north.
This may have another implication. Between Siberia and Alaska is Beringia, the land that we forgot. During the ice age it connected the continents, and it was were people lived before the migration into the Americas. The brief warm interlude 40,000 years ago, and the lack of glaciers afterwards, may be how the would-be Americans arrived at and survived in Beringia, prior to their long march south. Sometimes after 20,000 years ago, the Beringians moved west into the Yana region to replace the local populations. Probably this is the same time that other Beringians moved east to become the native Americans. Did sea level rise force them out of their habitat? Did they too have their climate change deniers, saying that all this warming was nonsense and should be ignored? It is such a human response: I’d love to know. There was a later, second migration across the Bering strait from this region which gave rise to the Inuit and the NaDene-speaking North Americans.
The Verkhoyansk mountains are an enigma, a terra incognito in our own backyard. It remains inaccessible and unnamed. Such places do still exist. But the region is part of our lives. It has shaped our world, and acts to both separate and join Russia and America. It has brought us riches, but also the shame of the gulag archipelago. And it is becoming yesterday’s world, abandoned and forgotten. Some places are just too hard.
Albert, June 2020