Is this the strangest egg in the world? The shell contains no egg white, yoke or embryo, nor even chocolate. No bird will ever hatch from it. Instead it is filled with a stony mineral. Which creature laid it, and what was expected to emerge from it? The only thing that comes to mind is a stone eater, from Nora Jemisin’s volcanic masterpiece The Fifth Season. But that is from another world.
There is a story here. This is about an Easter egg hunt with a difference. Forget about bunnies. Think dinosaurs.
Easter is the season of eggs and rabbits. Actually, those are a bit of an add-on. The importance of eggs came from a religious prohibition on eating eggs in the week before Easter – eggs harvested during that week would be kept, decorated and given to the children at Easter. (In some countries, including Ukraine, the eggs are painted red.) The Easter bunny stems from a German tradition but was originally a hare, not a rabbit. Easter has become a mismatch of traditions. The word Easter itself has a Germanic origin, although the precise meaning has been lost in time (a likely meaning is ‘dawn’); strangely, the word is now only used in English. Chocolate as an Easter tradition was a commercial invention. (The modern redefinition of Easter egg as a hidden quirk in computer games has nothing to do whatsoever with Easter and helps to keep you hooked a bit longer, to be exposed to more adverts.)
Behind all these traditions (except the commercial one) is the season of new beginnings, a restart, regrowth or resurrection after the desolation and perhaps hunger of winter. Many cultures celebrate this, each in their own way. Spring is when the world springs to new life. Originally this was seen as the start of the year, in a tradition which goes back at least four millennia. The 12 constellations of the zodiac form a procession with the bull at the head: at the time the constellations were invented the bull was April. The oldest parts of the bible use spring as the start of the year, while parts written after about 600BC have the year starting in autumn. In England, the start of the year was in March as late as the 17th century, something that causes confusion for the dating the Bristol flood. But the most important part of Easter remains those eggs – nowadays made from chocolate rather than cholesterol, although one can wonder which is unhealthier.Eggs are of course far older than Easter. The silly question of what came first, the chicken or the egg, has a clear answer. The oldest egg that has been found (microscopically small) is from 600 million year ago whilst chickens spread around the globe only in the last 2 millennia. Although eggs are thought of as associated with birds, many other animals do lay eggs, from sea horses to snakes. It is rare among mammals though: only the platypus and several species of echidnas, both limited to Australia and New Guinea, are egg layers. In spite of our confused Easter traditions, bunnies are not known for their eggs.
Dinosaurs, like the birds that descended from them, laid eggs. One may wonder whether they also sat on them (which would be one way to explain their extinction). We own a dinosaur egg. Actually, we own a clutch of them, acquired in mysterious circumstances. We know roughly where they were found. Our eggs are adopted from a duck-billed dinosaur mother (whom obviously we never met) from some 80 million years ago. The fossil eggs are very useful in school science talks – it is amazing how many of the children recognize them as belonging to dinosaurs!
Fossilized dinosaur eggs are surprisingly common. The eggs come in a variety of shapes, from spherical to very strongly elongated, and are not quite as large as you might expect from such a large reptile: ostrich eggs can be larger. The shells are up to 5 mm thick, depending on species, and in most cases the egg has the same curvature at both ends, unlike the pear shaped eggs of most birds. (Egg-shaped eggs can only be produced one per ovary at a time. Symmetric eggs roll of the egg bandwagon in one go.)
Most known dinosaur eggs come from only a few types of dinosaurs, mainly from the Cretaceous. Most are in fact late Cretaceous (100 – 66 million years ago), as are our eggs. There is a simple cause: the earlier dinosaurs mainly had soft-shelled eggs, like turtles, which don’t fossilize well. The hard-shelled eggs (with a thick calcite layer) developed in some species (independently from each other) and perhaps never in others. This may be related to how the eggs were cared for: whether dug into the sand, as in turtles, or kept in nests or clutches on the surface.
Most fossilized eggs have been found in clutches on the ground. (Not in trees, for obvious reasons.) The eggs are surprisingly strong. Even an ostrich egg is strong enough to stand on (don’t do this when mother is anywhere near!) and dinosaur eggs were a lot thicker. Still, it would be unwise for a very large dinosaur to just sit on her eggs. No shell weak enough to allow hatching could have withstood that kind of pressure. But many dinosaurs (at least those with hard-shelled eggs) did stay with their eggs. There is one known fossil of a clutch of eggs with the remains of a mature dinosaur, which is interpreted as the dinosaur either protecting the nest or even brooding. How normal that was we do not known, but it is assumed that this was not uncommon behaviour, at least among some species. Smaller oviraptorosaurs laid their eggs close together: calculations indicate they could sit on the eggs without breaking them. Larger oviraptorosaurus species instead left an opening in the middle of the eggs, meters wide. These dinosaurs were much too heavy to directly sit on the eggs: the nests suggest they would have sat on the ground in between the eggs, covering the eggs without putting too much of their weight on it. Oviraptors were feathered – perhaps to be benefit of the eggs rather than the parents. But the home care was not universal: no adult titanosaur bones have yet been found near any of their eggs. Was food an issue? A dinosaur needed to eat a lot and the vegetation would quickly have run out when staying in one place, especially if they were flocking together. So many things we don’t know!
We do not know how widespread brooding was among dinosaurs, but it seems a good bet that the hard-shelled eggs were hard-shelled for a reason. Soft-shelled eggs are more likely to have been left to it by the absent-minded parent. Good parents are also more likely to leave fossils!
We know very little about dinosaur parental care after hatching. Behaviour doesn’t fossilize well. As the eggs appear to have survived mostly complete, it is likely that the young immediately left the nest. (A growing baby dinosaur would have trampled the egg shells to bits.) Afterwards, it may have been a matter of staying out of the way. The young might have been too small (perhaps 10 cm) to be easily visible (let alone guardable) to a 10-meter long mother! They were in charge of finding their own food. There are some cases where a large number of bones from immature dinosaurs were found together, of different species. Perhaps these flocked by size rather than by species. But that is where our knowledge ends. The mortality rate for the first year or so will have been close to 100%: young dinosaurs would not have had it easy. Growth rates were typically around a doubling per year although this varied widely between species. Some (for instance the tyrannosaurus) grew large through a growth spurt, others quietly grew large over decades. I guess it might have been best not to be a tyrannosaur half the size of the neighbour, as this would make you seem like a good bet for a satisfying meal!
To fossilize an egg
Eggs don’t really need fossilizing. The shells (at least if hard-shelled) are already made from calcite, so in a way they are oven-ready to become fossils. Survival of the whole egg shell does require that they were left reasonably undisturbed. I guess being sat on by mother dinosaur would in most cases do that! An egg-eating snake might think twice before risking that.
Eggs were laid in favourite places. There are some 200 sites in the world where dinosaur eggs are found, and where they are found they can be very common, even in stacked layers. Fossilized dinosaur eggs had been laid in sand (either beach or dunes) or on flood plains. Ours were laid on a flood plain in an area with meandering rivers, a bit like the area of the Dinosaur National Monument. This would have been a semi-arid plain with good plant growth near water, but subject to occasional flooding which could cover the eggs in sediment. Slow floods (sheet-flooding) would leave the eggs in place within the nest. A fast flood would scatter them randomly over short distances. A flash flood would shatter the eggs and move the fragments over large distances. All of this is seen in fossilized eggs. Fossil eggs were mostly buried in sandstone or mudstone. Instead of sediment, volcanic ash could also do the job. The main constraint for fossilization is that the sediment or ash should not have been too acid as this would dissolve the shell. Acid rain might also have been a problem for the egg survival.
Once safely buried, the inside decomposes whilst the egg shell survives. Sediment can now enter the shell through any holes. This provides interior support to the empty egg shell against the weight of the sediment above. But in many cases, this was too little or too late, and only the lower half of the shell survived whilst the top half collapsed. When you see a fossil egg in the shop embedded in a sandstone matrix, be aware that it may be displayed upside down. In those cases, only the bottom side was cleaned from the rock. The top half was not excavated because it may be in much worse shape – or may even be missing.
[Not all dinosaur eggs for sale come from the ground. They are also made in factories. It takes more expertise than I have to recognize a fake egg from a real one! The rule of thumb is that if it looks too good to be true, it probably is too good to be true, regardless of how expensive.]
Finding embryos inside a dinosaur egg is a rare occurrence. The hatchling would have emerged through a hole in the egg, but much of the shell stays behind. The sediment that covers them is oblivious to the hole, or even whether the egg is full or empty.
Volcanic ash can be a perfect egg fossilizer. It is both lightweight (thus allowing the egg to stay intact) and an effective deterrent against egg predators. In contrast, lava is not recommended as it plays havoc with eggs. Fried eggs don’t make good fossils.
Volcanic rocks are often riddled with holes, like an inedible version of a Swiss cheese. Gasses within the lava creates those holes while the lava solidifies. It can also happen in sediment with organic material: as the material decomposes, a hole is left behind. And some materials come with pre-formed holes: coral comes to mind.
Nature abhors a vacuum. Where there is a hole, something will try to fill it. Water percolates through the rock and dissolves minerals. It enters the holes and stays there: over time, the dissolved minerals begin to cover the walls with a solid layer. Dissolved silica is deposited as agate. The image below shows such agate inside a coral. The silicon is deposited in layers, and these are often clearly visible in the agate. A wide variety of colours are possible, depending on the trace elements and the crystal structure. But be aware that agate can also be artificially coloured to make it more saleable.
Agate makes for a popular gem. As an aside, the name comes from the river Drillo in Sicily. The association may not be immediately obvious, but at the time (350 BC when Sicily was a Greek colony) this river was known as Achates.
Agate commonly forms from volcanic material. The original agates in the Drillo river were from the ash of Etna. The ash can be SiO2-rich (rhyolite) or SiO2-poor (andesite, basalt). SiO2-rich agate forms the spherical so-called ‘thundereggs’, while agate in basalt forms in less regular cavities. In all cases, they are formed at some distance from the original eruption, such as at the margins of ignimbrites, and require interaction with water. Making an agate is a slow process, in fact one that has not yet been replicated in the lab. But it has happened a lot in the real world. The oldest agate dates from more than 3 billion years ago – they are as old as diamond.
The agate egg
The National History Museum in London has a large collection of minerals – almost 200,000 items. (It is also well known for its meteorite collection.) Only a small fraction is on display. One of the items kept in storage was a beautiful spherical agate, donated in the late 19th century. It was recently selected to be displayed not to the public, but in an area open to members of the museum. The rooms here are named after Mary Anning, of Jurassic coast fame.
The agate in question is shown at the top of the post, on a photo provided by the museum (with apologies for the background colour apparently inspired by our Blue Lagoon revamp). The agate completely fills a thin shell of spherical rock. That in itself is unusual: the holes filled by agate are typically more irregularly shaped. The story from the museum tells how the curator noticed the similarity to another specimen seen in France. It shared the shape, the thin rim and the dark agate towards the centre. The French specimen was obviously also an agate, but the rim was classified as a dinosaur egg! This combination is uncommon but not entirely unheard of. It turned out that this was also the explanation for National History specimen: a dinosaur egg had been agatised.
The fossil museum egg clearly shows the impression of other eggs: it had been part of a clutch. It is not clear whether the egg had hatched: there may be a hole at the back in the image on the top of the post but it is not clear whether this is original or made investigating the content. The egg was found in ancient volcanic ash associated with a volcanic eruption. The embryo (if not yet hatched) would have succumbed quickly when the ash cut off the air supply but the ash layer was not deep enough to crush the egg. Some time after the explosion, water began to enter the egg and the deposition started. It turned an unborn dinosaur into a fossil gem, a true Easter egg.
It all happened in India.
India has several sites with fossil dinosaur eggs. Some of the sites are among the largest collections in the world. One of the fossils shows an egg, a hatched baby dinosaur – and a snake with a wide open jaw, ready to eat either the unfortunate 50-cm hatchling or one of the other eggs. All had been buried together in a sudden mudslide. So now we know that young dinosaurs had to survive scary predators.
The first dinosaur in India had been found in 1828. William Henry Sleeman discovered bones of what later became known as a Titanosaurus Jainosaurus, (one of over 100 species of titanosaurus now known) from a site on the slope of the hills above Jabalpur. Detailed surveys of this site were done a century later, most famously by Barnum Brown of the American Museum of National History. Brown was already known for the first discovery of Tyrannosaurus Rex. On the steamship to India he met a young woman, and on arrival they married. Lilian and Barnum Brown spend their honeymoon collecting dinosaur fossils. Lilian later wrote a book about it, with the title “I married a dinosaur” and sub-title The light-hearted story of a strange honeymoon in Indian and Burmese jungles, hunting big game that had been dead for million of years. The bottom line was perhaps to be wary of whirlwind romances! Barnum was too pre-occupied to properly write up all the discoveries. But although there was a detailed older description by William Sleeman of the location, the vegetation and the monsoon rains has changed the region and the site of the original fossil and Barnum Brown’s excavations was lost. In “The Age of Dinosaurs in the Land of Gonds”, Chatterjee describes how he went to locate it: “One day, after a futile week-long search, Sibani sat on a rock for our midday lunch break. I suddenly realized that was no rock my wife was sitting on, it was in fact a sauropod femur! The site matched perfectly with Captain Sleeman’s 1828 description of the bone bed close to his bungalow, where he found fossil fragments of animals and plants in the sediments below the Deccan Trap.”
India had separated from Africa, Antarctics and later Madagascar by the start of the late cretaceous, carrying with it its cargo of dinosaurs. The diversity of species in India was not great, but there were a lot of them and they evolved into a unique community while the continent drifted north into the Tethys. If you are desperate for Bruhathkayosaurus, Rajasaurus or Jubbulpuria, cretaceous India is the place to go. There were different species of dinosaurs well known from other continents: titanosaurs, abelisaurs, ankylosaurs. The final, youngest layer with dinosaur fossils is the Lameta formation which is widespread in western and central India and dates from the late cretaceous.
The Indian continent at the time was still much closer to Africa than to Asia, and was some 20 degrees south of the equator. It was larger than India is now: as much as half of the continent has since been lost in the Himalaya crumple zone. It was similar in size to Australia.
Now the trouble began. As India moved north, it approached a hot spot. Once it began to overrun this, the heat melted the bottom of the plate and eruptions flooded the newly formed continent. The Deccan traps had begun, to the detriment of the local dinosaurs.
The Deccan traps are among the largest continental flood basalts, although part of the lava is off-shore in the Arabian sea. The eruption was associated with the rifting between India and the Seychelles. The eruptions lasted for 8-10 million years but most of the eruption happened within a 1 million year period.
The traps contain multiple individual flows or sheets, separated by sediments. Those sediments are called intertrappean beds, and they are meters thick. They must have taken centuries to millennia to accumulate: the Deccan eruption clearly was intermittent. The iridium layer from the Chicxulub asteroid impact which put a full stop to Dinosaurian existence has been found in one of these sediment layers, a 6-meter deep intertrappean bed. That the Deccan traps had a role in the dinosaur extinction is not in doubt. That it was the sole cause is a much more controversial position, although it has been argued and it may have been true locally in India. For the worldwide extinction event, the Deccan traps has an alibi. It wasn’t there.
The Deccan traps erupted in several phases. The first phase started around 67.5 million years ago, and the later phases happened 65.1, 63.2 and 62.8 million years. 50%-75% of the volume of the Deccan eruptions came a few hundred thousand years after the asteroid impact. The dates do depend on where in the Deccan traps (and how) they are measured. The above dates are measured in the western provinces. In the northern Malwa plateau, the first phase is dated to 66.35 to 66.05 million years, followed by a brief interlude before the eruption resumed at 65.95 million years. Global temperatures increased at 66.5 million years, suggesting the Deccan traps were well underway by that time but went back to normal at 66.1 million years indicating a reduction in eruption rate. The Chicxulub asteroid impact was 66.0 million years ago. A new warming spike happened 25,000 yr before impact but this was smaller and short-lived. Immediately after the asteroid impact, temperatures dropped like a stone. The timeline indicates that the Chicxulub asteroid impact occurred during a lull in the eruption. Indeed, the location of the iridium layer in the intertrappean bed shows that the Deccan traps had been taking a break. The location of the Deccan eruption moved around over time with a tendency to move southwards while India migrated north. It is possible that the eruption continued somewhere in the traps, but at a much reduced rate.
Global environments were unstable in this era. Sea levels had been falling, perhaps because India was passing over the hot spot which previously had been pushing up the sea floor. In America, a sea arm of climatic importance dried up. The significant warming half a million years before impact suggests that the first Deccan phase started furiously with a lot of CO2 emission but tapered off over time. It was a hard time to be a dinosaur. Large animals may not be quick in adjusting to ecological changes. It is hard to learn to eat grass when you are build to eat trees! (Some dinosaurs did indeed manage to eat both.)
The Deccan and the egg
Back to the present-day Easter egg hunt. Dinosaur extinction worldwide may be dated to a quiet time in the Deccan eruption, but any dinosaur in India would already have had a bad time. There are a lot of complete but empty eggs in India: was this because of a low hatching rate? That could be related to Deccian pollution of the atmosphere and water. One can imagine young Indian dinosaurs en masse disrupting dinosaur society in their extinction rebellion protests.
Our egg was found somewhere in central India (according to the museum), and was associated with Deccan ejecta. There is no reason to associate it with the main extinction event itself: we are probably looking for an early eruption phase. It would also not have been within a lava bed as that would have ruined the egg. We are looking for ash. The location of the find is not reported, other than ‘in the centre of India’. A plausible location may be in the north central parts of the Deccan traps where the eruption was focussed in its early phase, in a region not covered by later eruptions. This would date the egg to the 1 million years or so before Chicxulub.
An interesting aside is that this is the same area where Jabalpur is located, which is where William Sleeman found his titanosaurus which Chatterjee’s wife rediscovered. The egg was originally found somewhere between 1817 and 1843, which is around the same time. And best of all, the egg appears to be that of a titanosaurus.
I decided to check this. The museum wrote that the egg had been discovered by Charles Fraser who lived in India between 1817 and 1843. It should be possible to find out where this person had lived! A search showed up a Charles Fraser, Lieutenant-Colonel, 1799-1868, who had worked as an Indian administrator from 1817 to 1843. That was our man. The blurb at the National Archives said that Fraser was in the Bengal Civil Service during 1817-46, served in Saugor and Nerbudda Territories, and was Commissioner of the Saugor Division 1837-43. These territories were captured by the British in 1818, with the Territories being set up in 1820 (so the starting date was a bit jumping the gun) – and the capital of the region was Jabalpur. The guess was right!
Fraser had left the territories in 1843 but apparently stayed in India until 1846. As the find was dated to the period 1817-1843, it places it within these territories. There was an uprising in the area in 1842, and after this a new governor took over – our friend Sir William Sleeman! In fact Sleeman had worked in the same administration as Fraser since 1820, though in more senior positions. His find of the titanosaurus was in the local Lameta formation. It seems plausible that Charles Fraser found his ‘stone’ in the same region. It is tempting to think of them exploring together, William Sleeman finding dinosaur bones sticking out from the hill slope while Charles Fraser stumbled over a strange looking stone – the titanosaurus’ very egg! But that would be too good to be true.
Jabalpur is located just north of the Amarkantak plateau, southeast of the Malwa Plateau. The latter is well dated, as mentioned above. The Armakantak has given some younger (post-asteroid) dates but the titanosaur find shows that there were also Deccan eruptions before. Those older dates still need to be measured. It seems plausible that they will be co-eval with the voluminous Malwa eruption, but that remains to be proven. Fraser is reported to have lived in Saugor from 1831 to 1833 and possibly later as well and this is on the edge of the Malwa plateau itself: it is entirely possible that the egg was found there.
Could Charles Fraser have recognized the stone as a dinosaur egg? Why did he collect the strangely round stone and open it up? Did he expect to find agate, or was he hoping for an embryo? The word ‘dinosaur’ had not been invented yet but that is a minor detail. The first confirmed dinosaur egg was discovered only in 1923, a century later. So Fraser might have had a suspicion, especially since there were apparently several such stones together, but he could not have known for certain.
As an aside, Jabalpur was a major centre in the kingdom of the Gonds, the region after which Gondwana (‘land of the Gonds’) is named. It seems kind of appropriate.
Fossilizing an egg within the Deccan traps is only the beginning. Any child knows that an egg is for opening, to find the treasure inside (and hoping it will be chocolate!). This egg is special because of the agate stone eater inside. How did that get there?
The museum wrote that the agate formed shortly after the egg was laid. That is conjecture. Agate has been found in the Deccan traps: it formed within cavities in the basalt and has been unearthed in mines. But this agate did not form during the Deccan eruptions themselves. It has been dated variously to 55, 45 and 22 million year ago, many millions of years later. This is probably climate related: the agate formed from weathering of the basalt, and it required a ready supply of water to the holes in the basalt. It took a long time for the right conditions to occur, depending on climate change and of course on the slow drift north. The rainfall and water pathways may have varied over time. Perhaps this is why we have not been able to make agate in the laboratory. We lack the patience.
In the case of our egg, we can therefore also assume that the agate filling also came much later than the egg. The minerals were deposited inside the egg as much as tens of millions of years after the reptile that had laid the egg had gone extinct. And much later still a mammal called Charles Fraser found the egg and resurrected it, to end up in a museum room named after that most famous of dinosaur hunters: Mary Anning.
An Easter egg hunt
And that is the story of our Easter egg. It tells of a time when the world was different, and when a continent was adrift in a foreign sea. The long reign of the dinosaurs would very soon be ending. The animal that laid the egg was oblivious to the disaster that was coming. The egg was never to hatch – whether from volcanic pollution or volcanic ash is perhaps a moot point. But although the world around it succumbed to fire and wind, and the dinosaurs disappeared into history, the egg remained and waited for better times. In the new Spring that was to come, a new season of the Earth, a treasure would grow inside, shaped by the very volcano that had killed the egg.
But the biggest treasure of the agatised dinosaur egg is the story it has to tell. It is a story of endings and beginnings. That is Easter.
Albert, April 2023
Read also Death of dinosaurs
148 thoughts on “The Dinosaur Egg Hunt of the Deccan traps”
Wow I guess Deccan Traps eliminated most dinosaur fauna in India or at least damaged it. Having avian loungs, or near avian ones, they dont take gas pollution well
Neither do eggs. Egg embryos don’t have a way to get rid of pollution
Hello over there on Avalonia, sort of a continent as well!
Great piece, lots of work.
Concerning tradtion the Orthodox don’t eat eggs after Ash Wednesday and hang an empty painted egg in a bush or some branches every day. This way you have forty on Easter Sunday, and if taken down one by one they are gone on Pentecoast, a very nice habit, esp. with children (even if you continue eating eggs). It might have developped to protect breeding times. So, the Orthodox are really vegan for seven weeks a year.
One day scientists will know more details. They might find out that most African and Indian Dinosaurs went down due to the Deccan traps, most American Dinosaurs after the impact and possibly a lot of Chinese (then much smaller and partly an island) and island Dinosaurs with the huge tsunami that would also have had dire consequences for Europe being partly an island nation at the time with a much smaller Atlantic Ocean. Besides the sea level, currents and temperature would have plaid a huge role.
Fruits of conifers might have been food for some species for a long time, and conifers might have been reduced as blossoming plants and insects had appeared. It might also be due to the insects that flying dinosaurs had less hardship whereas foraminifera and plancton are said to be sensitive.
Nothing ever was monocausal, not even the birth by a virgin. This is certainly a never-ending field of learning.
Thank you for this wonderful report and its as-ever wondrous asides.
Wonderful post, so much depth here.
Thinking about the Deccan, It makes me wonder about Yellowstone and/or other continental hotspots we see.
What influences flood basalt behavior versus silicic volcanism when a hotspot tracks beneath continental rock? In other words, looking at Yellowstone, it transitioned from a flood basalt emitter (columbia river flood basalts) to a serial silicic caldera producer. At least, that’s the case if you believe that the source of the Columbia river basalts is the same as Yellowstone, which I don’t think is shared by everyone. Is it all just a product of the overlying bedrock? This has always been my general assumption since the behavior at Yellowstone changed as the hotspot tracked away from weaker accretionary continental crust to stronger more granitic crust. The stronger crust would allow for larger magma bodies to form, more silicic crustal assimilation, and more fractionation of the magma to produce the silicic magma needed for large caldera forming eruptions.
But there is something missing here – clearly there are more factors at play. If the thesis that a hotspot tracking over thicker crust results in more silicic volcanism, then surely the Siberian traps and Deccan traps would have experienced something akin to what we have seen at Yellowstone with larger magma bodies forming deep within the thick continental crust. Given, the hotspots of the siberian traps and deccan traps were on a scale that would dwarf what we see at Yellowstone, so that is obviously a major factor. But even so, you would still likely see silicic volcanism where the siberian traps or deccan traps are if the theory that thicker continental crust allows for the development of large silicic magma bodies.
My current view is that there likely **was** some silicic volcanism in these areas, perhaps in an enormous scale even. But the evidence for that… if it does exist is likely buried deep beneath the extraordinarily thick flood basalt formations, rendering any calderas or ignimbrites impossible to find. Any silicic eruption would have formed towards the start of a flood basalt outbreak, and would have then transitioned into a proper flood basalt after erupting. There is precedent for this as well. While these are poorly defined, there is evidence for some of the largest silicic volcanic eruptions ever occurring at the start of flood basalts in the Parana and Etendaka Traps which came during the breakup of South America and Africa, or the splitting of Arabia from Africa.
But that brings up another question – is rifting the difference maker? Clearly that’s not the case in Yellowstone, but for our other examples of silicic volcanism being voluminous in the initial stages of a hotspot flood basalt (Parana-Etendaka, Arabia, and others), there was a difference in that these hotspots caused plate breakup whereas the Siberian traps and other flood basalt eruptions that do not have much direct evidence of silicic volcanism did not cause any plate breakup.
At Yellowstone the height of the CRB was associated with very large silicic volcanism at the McDermitt volcanic field, directly to the south of the largest dike swarm of the CRB. It was one structure, huge bimodal silicic volcanoes that periodically drain out their deep magma systems, the VEI 7 calderas of McDermitt might all be associated to flood lavas, like Askja in 1875 except 3 orders of magnitude larger, 4 for the lava. The lava floods declined in frequency after the Owyhee-Humboldt caldera formed about 13 million years ago, the first VEI 8, but still happened as recently as 6 million years ago and flows over 1000 km3 that reached the ocean were happening as recently as 11 million years ago. And even today mafic volcanism is very powerful in this area compared to most continental settings, the Snake River Plain us a full km of basalt, and its most powerful volcano at Craters of the Moon has potential to do fissure eruptions almost as large as the biggest in Iceland, there are a’a flows 30 km long on flat ground, as large as the outflow fans of the Laki flows, its a real monster of a volcano that deserves attention.
I have never really got the whole idea of the craton snuffing out the plume. Those arguments were based on the plume being under the SRP and now going under mountains, well how fid the SRP form… really, looking at North America from afar, it looks like the basin and range terrain for the whole northern half of the continent is oriented around Yellowstone, like a bow shock as the plume is tearing the continent apart in its wake.
Deccan was caused by Reunion, which is not the largest of plumes, actually very similar to Yellowstone, although very active. It might have been the rapid movement of India that initially prevented eruption until the whole thing was underlain by magma and it all went at once when a breach eventually formed, only speculation of course. One only needs to wonder about the scale of eruptions that would result from a really powerful plume like Hawaii or the Galapagos being overrun by a continent…
Chad Reunion plume was much stronger back then then it is today I guess
It was formed in Cretaceous No signs it was there before Deccan Traps
There is a cretaceous Age submerged Hawaii Mega LIP in Earths mantle below Asia so Hawaii plume was also spawned by a Superplume Event
That’s just it, we don’t know the lifespan of these ‘plumes’ if that is what they are. Efforts to trace them backwards, or from an LIP to an ongoing spot of volcanism usually falls flat.
Iceland is probably the biggest example of this with theories that have the plume head passing over Greenland, maybe something to do with the North Atlantic LIP/High Arctic LIPs and possibly even the same one as the Siberian traps. Likelihood is it formed in place and the mid-ocean ridge bent towards it.
Galapagos – Carribbean Plateau – another one that makes very little sense.
There is a massive oceanic LIP under Asia thats been resolved by mantle tomography and other studies
Thats the subducted Hawaii plume breakout LIP that occured when the massive Hawaii plume formed, and unlike many other mantle plumes that are only strong at birth, Hawaii have remained insidously strong even after the first phase, Infact Hawaii retains a plume head, while many other weaker mantle plumes are just stalks. Hawaiian plume is also undergoing a major sourge in supply since Oahu formed as well.
No way that plume is subducted. That special plume is under Big Island.
You are possibly thinking of a flood basalt. However, as the Pacific Plate rotated anti-clockwise – it’s assumed – with the birth of the Ontong Java Plateau (possibly Louisville Plume) the Shatsky Rise might be associated with the Hawaian mantle plume. Tamu Massif is no dwarf either.
Probably misunderstood. You meant the LIP, It just might not be dubducted as due to rotation the flood basalts are often at some distance.
sorry for misinterpreting
I mean the first LIP of the Hawaii Hotspot thats been subducted long ago below Asia
The Hotspot dont move anywhere but the seafloor does
Might let you know, insidiously means the same as saying it is evil or has bad intent, it isnt another word for ‘big’.
I dont think plumes are evil though maybe very destructive to the biosphere at times 🙂
Reunion plume was probaly at its Max strenght when it Did the Deccan Traps and it have cooled alot since then. At its Max strenght it probaly was quite a bit more powerful than Hawaii is today
And the CAMP plume was stuff of nightmares when it was at its peak 🙂
But these plumes are very powerful at start but seems to cool off quickly and loose their plume heads becomming just small specks afterwards ( still Reunion is an absolute monster compared to most Non Hawaiian volcanoes today )
Hawaii was lucky remained very powerful after its flood basalt episode, ( I can just imagine how very powerful Hawaii was when it formed, surfaced in the Cretaceous during its own ”Superplume Phase”
I don’t believe that rifting in Yellowstone is a point as Yellowstone is young, and rifting might happen in the future. Last but not least there are at least three failed rifts in the middle of the United States, the Mid-Continental Rift, the South Oklahoma Aulacogen southwest of it and the Reelfoot Rift southeast. Yellowstone is west of all of them resp. southwest. As the continent moves and rotates, however, a rift might develop at some point in the deep future.
The NAIP, CAMP and Paranà-Etendeka might have developped first, and then the rifting happened. We often underestimate timing. The opening of Pangaea would have taken a long time, s.th. between 30 and 50 Million years.
So I imagine that Yellowstone could be a preparation for rifting in the future as America plus Eurasia, firmly connected below Siberia is a huge continental mass that will break apart like contnental masses broke in the past.
Btw., a suspected rift, Lake Baikal, shows no volcanism at the moment, but there was possibly volcanism in the past. Side note: Not completely sure whether Lake Baikal is a rift at all.
To be added: Rifting might need a Triple Junction like Afar. The only Triple Junction there is the TJ near Mendocino, 1.150 miles to the southwest.
Lake Baikal does show volcanism but nearby, not in the immediate vicinity. Not much in the way of a thermal anomaly however, unlike the Rio Grande (Socorro). I’d say that points more towards other processes causing the shear like the Pacific slab-pull effect coupled with the Himalayan orogeny. Probably a fair bit of extension there – let us not also forget that it is near the edge of the Siberian craton and edge-driven convection can cause upwellings.
It seems to be less frequent in present day, but the volcanic fields around the lake are pretty large and activity has been going on since the miocene.
Correct me if I’m wrong but doesn’t the volcanic activity related to the Baikal rift stretch all the way into Mongolia?
In dont think yellowstone is powerful enough to rift the North american continent, that requirues a ”Superplume Breakout”
Still as a continetal volcano Yellowstone is a monster, capable of obisidian flows with volumes of 10 s of km3 and basaltic flows as large as Laki. While not a doomsday volcano, its still a monster, so the dumb tinfoil hats have at least something right.
An effusive eruption at yellowstone caldera is the birth a whole mountain plateau so quite a sight
The last Yellowstone eruption ejected over 1,000 km3 DRE.
Laki Fires by comparison was only ~ 14km3.
Yellowstone, when/if it goes off, will alter human existence in ways unfathomable.
Fortunately, at this time the two magma chambers are mostly solid with less than 15% melt in the upper chamber and only ~ 2% melt in the lower/bigger chamber.
So, unless Yellowstone undergoes a period of rapid rejuvenation (which can occur in mere decades), then we are safe (for the time being).
But when/if it does erupt, it’ll truly be a doomsday eruption for millions/billions of people.
Yellowstone had an effusive rhyolite eruption 70k years ago.
I don’t agree that Columbia basalts were a result of a mantle plume. Crust was severely weakened by multiple orogenies/subduction events, the subducted plates were heavily fragmented, and the overly crust was being stretched like taffy, still is. It was inevitable, much like the Altiplano-Puna complex.
A couple of questions:
which way do the Deccan Traps lavas flow?
Where on the African continent/ Madagascan Island are their corresponding lavas?
The separation India-Madagascar had been completed well before the Deccan eruptions, and the separation from Africa was even earlier. So there are no related flows on either of them. The Seychelles were still attached and being rifted during the Deccan. There are related lava flows on the Seychelles platform but of course submerged. I haven’t looked up details of those. Most of the lava is on India (up to 2 km thick) and off the Indian coast. The total volume was likely around 1 million km3 (with significant uncertainty). The Seychelles would not have added much to that. So it was large even for a LIP, but both the CAMP and the Ontong-Java plateau were significantly larger.
Thank you Albert.
Is the Reunion Hotspot the heritage of the India-Madagascar divorce or is it the heritage of the Deccan eruption?
It is thought to be the latter.
May I add to this that they are in Central and West India. In the north-east there are smaller traps, the Rajmahal Traps that probably resulted over the Kerguelen Mantle Plume and left its own trace.
One researcher said that it is necessary to fly over the Deccan Traps to get an idea of the size although not all of them can be well seen as some is overgrown.
So, India travelled up there and left also two spreading ridges on the western and on the eastern side. The development of those spreading ridges and its influence on currents and climate might be underestimated.
Interesting article from 2015 about Speedy Gonzalez India
The whole story must have started at some point, and s.th. must have been the reason. So here is an article – abstract, not much reading 😉 about the Marion Plume and India’s plus possibly Madagascar’s mobile belts:
Besides, Africa was further west at the time. So India plus Madagascar might have separated from Africa where the African Rift is now which would make sense.
Antarctica had forests then and was further north.
It is difficult for nature to preserve the events over this long timespan. Often there is either no way to create sediments or there is too much erosion. Sometimes geological grabens can keep the past over long time.
In fact both Dinosaurs and Mammals came from the same family of reptils. Reptils (in my view) represent the development of the motor cortex of all species which once decended from them. Mammals separated around the Permian age, while Dinosaurs did a bit later (Triassic?). The different brain structure of birds and mammals shows this division.
Mammals are actually not really related to any other terrestrial tetrapods. Mammals are Synapsids while what we call ‘reptiles’ and also birds are Diapsids. the divergence was already complete back in the Carboniferous, although back then the only difference was that one group (Diapsids) had an extra fenestra in their skull, the two animals would have been very similar and at that particular point in time considered close relatives to an outside observer.
Problem is that most early Synapsids were considered to be reptiles related to lizards, an easy mistake to make, but then when it became clear they were closer to mammals it got confusing, so they got called ‘mammal-like reptiles’.
But now they are not called reptiles at all, because it was also discovered that birds would have to be considered reptiles too if crocodiles are because they are both archosaurs. So the word ‘reptile’ was just dropped as a formal grouping. The only non-paraphyletic definition of reptile now ends up being the same definition as that to describe the group Lepidosauria, which is the orders Squamata (lizards including snakes) and Sphenodontia (Tuatara). Crocodiles and dinosaurs (which include birds) are Archosaurs. Archosaurs and Lepidosaurs are what form the Sauropsids, the largest part of the Dispsids.
Synapsids didnt diverge like this, it was only one line really, with many branches that failed. Mammals are part of the Cynodonts, and this group was allied with the Therocephalians, Gorgonopsids, and the Dinocephalians, to form the Therapsids. Dinocephalians were still rather reptile-like, probably without hair and probably not completely endothermic, although many had an erect stance and glandular skin like modern hairless mammals. Gorgonopsids were probably more warm blooded, though not so much as modern mammals even sluggish ones like monotremes, they are best known for being the first case of sabre toothed animals. Therocephalians and Cynodonts were hairy and endothermic, even back in the Permian, maybe the first animals like this. Some therocephalians were also probably venomous 🙂
There was also a full 3rd group, the Parareptiles. These were Sauropsids but they split off very early too. This group went extinct at the end of the Triassic, but were mostly found in the Permian, most recognisable member is probably Scutosaurus. This group was once called the Anapsids, and included turtles, but now turtles are known to be related to archosaurs so are not part of the parareptiles at all and are part of the Sauropsids. Sauropterygians (plesiosaurs) and Ichthyosaurs were also considered yet another separate lineage, Euryapsids, but these too are now considered to be part of the Sauropsids,. Sauropterygians are possibly evolved from the Permian reptile Hovasaurus which was an early , while Ichthyosaurs are thought to have evolved from another unknown animal also from the late Permian, as even early Triasic ichthyosaurs were fully aquatic and sometimes enormous in size. But both of these groups are entirely extinct, so placing them in the tree of life is extremely difficult, these interpretations are bound to change.
So really, apart from mammals, all fully terrestrial tetrapods are Diapsids. The only thing that is less ‘reptilian’ than mammals are the temnspondyl amphibians, which evolved in the middle Carboniferous and one branch of which still exists as the modern amphibians (Lissamphibia). So you are more reptile than a frog is but much less than a chicken is 🙂
Or, that mammals and birds are a perfect example of unrelated groups evolving to be similar animals, evolving from an ectothermic scaly thing with a long tail and 4 sparwling legs (a ‘reptile’) into another thing that stands with erect legs and is endothermic and covered by keratinous fuzz, which got extensively modified at times.
Or if you dont want to read that then you can look at this picture 🙂
Thanks Chad. I had read it but this diagram demonstrates it clearly.
Thank-you for your comment and correction, Chad!
I had some introductory paleontology, but not on this professional level. How can we understand the “Synapsides”? Are they some kind of “embryonic mammals”? Maybe the embryonic growth of individuals reveals the historical evolution. The historical development of the brain and neurologic system was first the motor stage, second the sensory/feeling stage and third the higher (cognitive) brain.
Synapsids are all animals that are either mammals or are closer to mammals than to either birds or lizards. The first thing called a ‘reptile’ in the fossil record was Hylonomus, which would have looked like a lizard and lived in the Carboniferous 316 million years ago. The divergence of Synapsids was still earlier than this though because Hylonomus was already on the Diapsid line.
There isnt a good word really, because the earliest Synapsids would have looked basically like lizards. But the word ‘stem-mammal’ is preferred. All Synapsids in the fossil record are closer related to mammals than to any animal called a ‘reptile’ in the modern day. And it is only early forms like Dimetrodon that were like this, formerly called ‘pelycosaurs’ but this is a paraphyletic group. Dimetrodon was part if the family Sphenacodontidae. This family evolved into the Therapsids, which are the the Cynodonts, therocephalians, Gorgonopsids, Dinocephalians, and a 5th group I forgot to add before, the Anomodonts. Most of these, as above, already looked at least somewhat like mammals even far back in the Permian. One group of basal Synapsids persisted to the P/T, the Varanopidae, they actually did look like lizards, but their actual status as Synapsids is disputed too. There is a coprolite from the Permian that has hair, it proves that hair evolved before mammals fully evolved.
I also got the ‘reptile’ definition the wrong way. All amniotic tetrapods that arent Synapsids are Sauropsids. The Sauropsids are further divided into the Eureptiles and the Parareptiles. Hylonomus above was a Eureptile. The Parareptiles are entirely extinct since the Triassic. Their divergence point must have also been before 316 MYA.
Eureptiles are composed of the Diapsids, and a lot of uncertain paleozoic ‘reptiles’ not classified otherwise. The Diapsids are as described, the common ancestor of lizards, crocodiles and birds, and all of its descendants.
You’re a treasure trove of information, Chad. This is me subscribing to ‘Chad’s Dinosaur Facts.’
Sorry this is OT for this thread, but looked like quite interesting article with a link to paper coauthored by clive oppenheimer in it
In my view the 14th century was the most apokalyptic one of the last 2000 years. It was the beginning of the Small Ice Age with storms and floods. It had major earthquakes in usually quiet places. It hat the apokalyptic “Grote Mandrenke” 1362 with thousands of deaths. Finally the Black Death ended Europe’s high medieval culture and killed in masses. Maybe volcanoes somewhere added to this. Hekla 6 was in 1341 according to Wikipedia’s list, and Öräfajökull’s eruption 1362 (the same year as the Mandrenke).
Do remember the Magdalen flood https://www.volcanocafe.org/the-1342-st-mary-magdalene-flood/ and of course the demise of half of Greenland’s colonies https://www.volcanocafe.org/vanished-vikings-of-the-west-demise-of-the-western-settlement
I remember that I once read this article. The Magdalene Flood was an event like the Noachian flood. Something which heavily would challenge the resilience skills of our technical age and hybris. Maybe the biblical mythos bases on a mesopotamian version of this kind of flood during the early human history.
Periods of major changes in climate can be accompanied with weather events which otherwise are unkown. We also have to expect such unpredictable event during the present climate change. But we don’t know what it will be. One certain example are droughts. They begin slowly and boring, but they can hit a country as hard as a flood.
At the beginning of the Little Ice Age there was one more frightening event: The progress of Alpine glaciers. Imagine you live in a small village in a beautiful green valley, and the glaciers are coming like a slow-motion ice tsunami.
Of course we had a flood like the Magdalena flood just recently in the west of Germany. Whether similar weather pattern and similar amount of rain, just a 100 miles further north
The flood disaster of 2021 was in my view related to certain physical topography of the Ahr’s valley. It is a somewhat dangerous V-shaped valley which from time to time makes terrible floods.
Indeed Central Europe is generally vulnerable for stationary depressions which are caught between Scandinavia and the Alpes. They can mix polar cold air with warm, wet subtropical air and cause a lot of rain over several days in an area which is not used to it (unlike f.e. Ireland, Vancouver, westcoast of Norway). 2002 one of those depressions hit Czech Republic and Saxony. 2021 was more to the west on the Rhine river system.
A much bigger deal than the Magdalen flood is the St. Lucia Flood. It was estimated to kill 50,000 in Germany and in the Netherlands it turned a large fresh lake into the Zuiderzee and also much of Zealand dropped below the waves. Now part of this was that between peat mining and draining for agriculture (if peat is exposed to air it will decompose and compact) was reducing the ground level, thus increasing the vulnerability to sea invasion and dike failure, lot of other bad flooding events in a couple hundred year period around this, but the Saint Lucia Flood was by far the worst. Large parts even to this day have never been reclaimed from the sea.
It shattered the Frisian lands, much of Frisia quite literally ceased to exist, and the remaining land was broken up into units less able to culturally or politically survive. West Frisia’s dikes largely held, but it was now separated from the rest of Frisia by a 15km wide channel. Within 10 years, the Count of Holland would completely subdue them.
It is difficult to find accurate information about the St Lucia flood. It is thought to be the worst by about a factor of 2 in the Netherlands – if the numbers are correct (which would be a rarity in the Middle Ages), 10% of the Dutch population drowned. Floods in the Netherlands are caused by storm surges (which happen about once per decade), river ice (very common in the18th and 19th century, almost non-existent now) and river flooding, in that order. The Magdalen flood was very unusual for its type – at least so we thought until 2021 when it happened again.
Some of the effects Wikipedia attributes to the St Lucia flood of December 1287 already happened in the All Saints flood of 1170. This is when the river Vlie became a sea arm, Stavoren and Amsterdam gained a sea connection and Frisia and West Frisia became separated. But it is hard to know details of either flood.
The Magdalen flood was a river flood, while St. Lucia was a storm surge. The Middle Ages had obviously numerous deadly storm surges on the North Sea coast. The 14th century both had large river floods (Magdalan flood) and large storm surges. Also Black Death, the great earthquake in Basel and one of Örafajökull’s dangerous eruptions. Doomsday century for Europe.
This century supposedly also weakened the Scandinavian empires which until 1300 rivaled England much more than later.
There are many videos and images on that thread, it seems like a massive eruption. I can’t be sure whether the videos are real or not though, but they are probably from Kliuchi, near Shveluch, and it makes sense there would be people filming the ash fall and such.
I wonder which objects of our human civilization would be most prone to agatise or petrify?
Perhaps wooden sculpture and utensils? Some of the details could be preserved amazingly well, compare e.g. to:
The link was lost. I meant this image: commons.wikimedia.org/wiki/File:Lesbos_petrified8.JPG
Thanks for the interesting article!
Thee first picture in the article (before doing any reading) made me ponder, what is this???
In my collection I do havesome “eggs” looking like this…., but not quite.
“The ash can be SiO2-rich (rhyolite) or SiO2-poor (andesite, basalt). SiO2-poor agate forms the spherical so-called ‘thundereggs’, while agate in basalt forms in less regular cavities. In all cases, they are formed at some distance from the original eruption, such as at the margins of ignimbrites, and require interaction with water.”
I think you were writing a bit too hasty here Albert…. 🙂
Agate is a cryptocrystaline form of Silicium.
In SiO-rich rhyolite flows spherical so-called ‘thundereggs’ can be formed.
The cavities inside thundereggs are often star-shaped while in basalt the shape of the voids are more irregular.
looks like Shiveluch erupted today with 20KM ash cloud height. Satellite shows 3 distinct eruption so far.
Nice videos everywhere. But is this real or are people just copying stuff from people that copy stuff?
There are many videos and images on that thread, it seems like a massive eruption. I can’t be sure whether the videos are real or not though, but they are probably from Kliuchi, near Shveluch, and it makes sense there would be people filming the ash fall and such.
SO2 emission of this eruption seems to be about 0.2 Tg, according to prof. Simon Carn: https://twitter.com/simoncarn/status/1645662745638096896
For comparison, the Hunga Tonga eruption emitted about 0.4 to 0.5 Tg SO2.
Calbuco which has similar composition produced 0.295 Tg and 0.27 km3 of pyroclastic material in its 2015 eruption. So perhaps this eruption of Sheveluch is a low end VEI 4.
Tg of SO2
Sheveluch has been continuously effusing lava since July 2022, which I know from looking at MODVOLC infrared monitoring, strong thermal anomalies have been recorded for 9 months there. Another case of volcano doing a huge explosion during a prolonged phase of more gentle continuous eruption. Soufriere already did that in 2021. And Hunga Tonga also followed a short period of continuous eruptive active.
Some variegated comments from me…
First: I have many many friendly dinosaurs where I live. Some will perch on my hand! (The furry ones are marsupials not dinosaurs, but near enough is good enough.)
Then there are the Australian dinosaurs which turned into opal. Here is the famous Eric the Pliosaur. As a kid with my dad I even found a likely opalized dinosaur bone at Lightning Ridge – it was small, only a cm or so, but clearly was a bone of coloured silica.
As to the Deccan Traps my personal hypothesis is that they were on the other side of the planet from the Chicxulub impact location, and that seismic spallation caused cracking which allowed the magma to erupt in what is now India. There seems to be a similar relationship between the Permian asteroid impact and the Siberian Traps.
Lastly here’s some nice volcano bling:
Video: 13 volcanoes seen from space (Phys.org, 10 Apr)
by European Space Agency
VC customers will know all the volcanos, except perhaps the caldera in Chad. The video is excellent though!
Huge eruption this morning at Shiveluch in Kamchatka!
Plume estimated at 16km high
A screeshot from a video:
Sorry, this has been posted just before, if sb can delete these messages.. Sorry for the SPAM !
We much appreciate these reports! Valid reports of eruptions are not considered spam here! It is what we are here for. Dinosaurs are just for passing the time. This is for real.
Not to repeat myself but this article of yours was absolutely brilliant from my perspective! I’ve read it three times already.
Thank you so much for your time and effort!
(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued: 20230411/0548Z
(3) Volcano: Sheveluch (CAVW #300270)
(4) Current aviation colour code: RED
(5) Previous aviation colour code: red
(6) Source: KVERT
(7) Notice Number: 2023-54
(8) Volcano Location: N 56 deg 38 min E 161 deg 18 min
(9) Area: Kamchatka, Russia
(10) Summit Elevation: 3283 m (10768.24 ft), the dome elevation ~2500 m (8200 ft)
(11) Volcanic Activity Summary: Strong explosive eruption of Sheveluch volcano continues. Explosions sent ash up to 8 km a.s.l., ash clouds are drifting about 430 km to the west-south-west and to the south of the volcano.
An eruption of the volcano continues. Ash explosions up to 15 km (49,200 ft) a.s.l. could occur at any time. Ongoing activity could affect international and low-flying aircraft.
(12) Volcanic cloud height: 7000-8000 m (22960-26240 ft) AMSL Time and method of ash plume/cloud height determination: 20230411/0314Z – Suomi NPP 15m16
(13) Other volcanic cloud information: Distance of ash plume/cloud of the volcano: 435 km (270 mi)
Direction of drift of ash plume/cloud of the volcano: WSW / azimuth 256 deg
Time and method of ash plume/cloud determination: 20230411/0314Z – Suomi NPP 15m16
Start time of explosion and how determined: 20230410/1320Z – Satellite data
That’s from about 4 hours ago. Big eruption.
Was Shilevuch dormant or active before this huge eruption?
There had been lava effusion since July 2022, probably building domes and making pyroclastic flows.
In the days before I’ve noticed more the action (and plume) of Bezymianny. When I first heard of the news that a volcano in Kamtchatka had gone off, I thought of this one and was surprised a bit, that Shilevuch was the one. The plinian plume of Shilevuch must have been much larger than the rather “columnimbus”-sized Bezymianny plume.
My guess is that Bezymianny was a punctual vulcanian explosion, while Sheveluch has been a sustained or pulsating plinian eruption.
Bezymianny (difficult to write) had a St. Helens like Plinian/Pelean eruption 1955. Its shape also reminds a bit to St. Helens with the dome-building inside the crater after the climatic eruption. The magma of Bezymianny is Andesite to Dacite. So similar to St. Helens.
Sheveluch is Andesite to Basalt, but more viscous than f.e. Stromboli. Why is it so explosive?
Bezymianny erupts crystal rich andesite, like Sheveluch, the dacites are from a series of flank lava domes to the south of the stratovolcano. Sheveluch has erupted mostly crystal rich basaltic-andesites and andesites, and very rare basalt. But during the Holocene Sheveluch has only erupted the andesites, if I recall correctly, so its viscosity and eruption style is as expected of its magma.
Stromboli has a very complicated chemistry that I don’t really understand much. It has some extreme potassium contents, belongs to a rare family of highly potassium rich, sodium poor magmas, that is best represented by the Italian volcanoes. Some of its lavas are crystal-poor basalts, and should be much more fluid than typical subduction zone lava, but these only come up during the big explosions I think. Usually it erupts crystal-rich (50% vol crystals) basaltic trachyandesites that are also relatively fluid because the interstitial melts are apparently not much more silicic than the total rock composition.
Sheveluch is pretty much the most productive lava dome volcano in the modern history I think almost always effusing pasty lava seems very similar to Soufrihere Hills
Soufriere Hills and Sheveluch are both crystal-rich andesites, with a highly evolved intercrystal melt. So it’s the same style of volcanism.
It was also a block of andesite which blocked St. Helens 1980. Maybe this is one main danger of andesite. It can better built a solid lid on top of a volcano than more softer types of lava. Then rising magma needs much pressure to shoot the plug away. In this event the gas pressure lowers very suddenly and fuel huge plinian/pelean explosions.
Yes very viscous and cool crystal rich, the remaining melt between is ryholitic even right ?
Yes the interstitial melt has 70 wt% SiO2, apparently, which falls somewhere between rhyolite and dacite. But the whole rock composition is 60 wt% SiO2, which is andesitic. Most dome building stratovolcanoes have such crystal rich andesites and basaltic-andesites, with highly evolved interstitial melts. Merapi, Augustine, Soufriere Hills, Sheveluch, etc
In this context, what exactly is ‘interstitial melt?’
Thank you so much Hector for all of your analyses and info on this event!
Thanks Ryan. Subduction zone stratovolcano magmas are usually a slurry of solid crystals and liquid melt. Often close to 50%-50% of each, although usually with a bit more melt than crystals. The interstitial melt is the part of the magma that is actually liquid upon eruption, the rest being solid crystals. Here the interstitial melt would be rhyolitic, but with mafic crystals in it, and the whole crystals+melt is an andesite. Presumably the andesite would have crystallized away certain elements and the remaining interstitial melt would be rhyolitic.
Unlike stratovolcanoes, calderas usually erupt crystal poor or even crystal free rhyolite. Probably because such volcanoes collect the remnant melts from crystallizing andesitic and basaltic magmas, and are kept in a hot molten state by the same convecting or boilup-drainback, basaltic or andesitic magmas.
If you think of lava as being like honey, then how crystallized honey still has liquid honey in it but is much more viscous. Or like how slushy ice has liquid water in it as well as ice. Its this except the liquid is a rock.
In this context Hawaii is like if you put that honey in the microwave on high until it is fully melted 🙂
Really though, the lava erupted at Kilauea and Mauna Loa is often completely crystal free, maybe a couple percent olivine. But even the 30+% crystals of the picrite eruptions like 1840 and 1868 are extremely fluid. Just looking at the waves that formed in the January lava lake, the melt has got an extremely low viscosity, wave lengths of only a couple meters and breaking at the shore.
Its a whole lot more complicated than SiO2 content evidently, given that Kilauea is not actually that low, usually about 50-51%, it is common to see basalts down in the mid 40s. Weird to consider that the SiO2 of Kilauea magma is a lot closer to that of Shevluch than it is to Nyiragongo… but it is true.
Thank you guys for the great explanations! I definitely have a better understanding now.
Yes its a temperature thing, higher temperatures kills the crystals and lowers polymerization, fagrdals was also insanely fluid in 2021 when it had its crystal poor phase.
Nyiragongo is also very crystal poor as well
And Etna is like very fluid concrete I guess
Smooth fluid alimumium looking lava flows are a good bet of low viscosity and nearly crystal free glass melt, Fagrdals looked like liquid aliumium in 2021 summer after the eruption dragged up crystal poor melts
I’ve gotten around to reading USGS/Smithsonian report on Sheveluch this week. Sometimes these dry reports have a bit of fear in them…
I think I would have “left the area” with alacrity too. Fifty two thousand feet? Wow!
Based on GVP this seems to be a relatively normal thing for Shevluch, at least it is a thing that happens every few decades. 1964 was a full lateral blast, since the 80s that scar has been filling with domes and ash, was mostly full last I saw, so maybe this is another mass dome destruction.
Hadn’t considered that, maybe the dome complex underwent a large scale gravitational collapse and then blew up. I suppose there will be an investigation to find out what caused this eruption, and if a debris avalanche is found to underlie the ash, then it will confirm this was a landslide-triggered explosion. The one in 1964 was triggered by a lateral slide of the volcano, but the ensuing explosion was a vertical plinian eruption, not a lateral blast.
0.36TG acc to the data i’ve checked (which is updated from 0.2). Based on everything i’ve read, found and gut feeling, this is a small to moderate VEI 4 to me.
Australian mainstream media report with video of the ash plume https://www.abc.net.au/news/2023-04-11/russia-volcano-eruption-aviation-warnings/102210562
this satellite GIF shows you the height and power I think. Over shooting tops just like a giant thunderstorm.
Albert this was truly a spectacular article and was a serious pleasure to read! These I think are my favorite type of articles on the site (reminds me of your Ghosts of Christmas Past piece).
When we think of birds as heirs of dinosaurs, we often forget the giant non-flying birds which indeed had the size of many dinosaurs, but became extinct. F.e. the Moas. They might come very close to some dinosaurs with feathers which were unable to fly. The ostrich’s eggs are not much smaller than many dinosaur eggs.
A lot of those giant birds also are only extinct because of ourselves too. Moa would certainly still exist for example.
Actually, even on continents with mammal predators there were or still are birds of large body size. It is only really because historical documents are predominantly from Eurasia that lacks large flightless birds, that the concept is somewhat obscure. Giant birds did exist, like Gastornis, back in the Paleocene and Eocene. Relatives of Gastornis survived in Australia until the Pleistocene.
North america also had Gastornis but later on it also had the Bathornithids,which were carnivorous, very similar to and probably closely related to the Phorusrachids of South America. So the last time a theropod heald an apex predator role in the US was in the Oligicene not the late Cretaceous. Or, even only 1 nillion hears ago, given the successful northern migration of Titanis into the Gulf states, it was significantly taller than any of the mammal predators it coexisted with down there 🙂
My personal idea is that some flightless carbivorous bird will evolve in the wake of our damage to the planet. Perhaps along with larger reptiles in some warm areas especially in Africa and northern Australia. This seems to have happened in the early Cenozoic, large herbivores were mostly mammalian but large carnivores were much more diverse. Had the Cenozoic not cooled down the apex predators might have been a reptile like Boverisuchus instead, or any number of birds.
There is one difference between dinosaurs and elephant birds: the size of the egg relative to the animal. Dinosaurs had a lot of small eggs (relatively speaking) while the large birds have a few large ones. That makes the birds vulnerable to egg predation. The main danger comes from predators with teeth. Moas were hunted to extinction – by rats. So (probably) was the Dodo. The large birds evolved in ecologies without a abundance of rats.
The extintion of the Moa and other giant birds by humans shows that humans also were a possible dangerous threat for dinosaurs if they had co-existed.
Probably the dinosaurs already invented feathers. We don’t know which how much, but they began it. Fossils mostly only bear the bones, not the skin and feathers. We need a lot of fantasy to imagine how they really looked like.
We have thousands of fossils of feathered dinosaurs 🙂 the biggest is a 1 ton tyrannosaur so they were not only small.
The earliest fossil with feathers is from the late Jurassic but are from many very diverged froups, ranging from early true birds likecArchaeopteryx all the way to ornithischian dinosaurs, which are thought to have diverged very far back in the Triassic maybe even near the P/T boundary. There is a great deal we dont know about Triassic dinosaurs, especially as even the earliest dinosaurs and pterosaurs show up already as rather derived animals. The earliest Dinosaur fossil is Eoraptor, but this animal already appears to be an early sauropodomorph, meaning the split of this group with theropods was earlier. To make things more complicated basically every Ornithischian lineage just appears suddenly in the early Jurassic, so there is a ghost lineage of some 40 million years. Many paleontologists consider the Triassic Silesauridae to be likely ancestors to the Ornithischians. The ancestor shared with Pterosaurs, which had a kibd of fuzz that is homologous to feathers, was probably an animal around in the aftermath of the P/T. The common ancestor with crocodiles and ancestral Archosaur itself, probably lived in the Permian, a derived pseudosuchian archosaurs existed a million years after the P/T.
Feathers, just like fur, are a thing that was evolved far before the nodern abimals that use them, both might date back to the Pernian, and certainly feathers existed since the early Jurassic.
So it is likely
Exactly Rats and rodents in that family only spread over the world relativly recently thanks to human transport activities. They are the worlds most sucessful mammals after humans in many ways. Being small, intelligent, able to eat almost anything and able to live in burying tunnels and exist in huge populations, rats are pretty much pre – adapted for the next mass extinction or for the biologica mass extinction that we humans are doing.
I do think Dixon is correct about the rodents versitalities, they will fill the empty roles of the lost Megafauna in the future, growing into giants ( unless humans turns entire Earth into cities and agicultural lands )
Chad can you motivate again why Rats woud fare poorly doing a global catastrophe? I see them as quite hardy althrough they cannot hibernate
Rodents have to gnaw on things to prevent their teeth getting too long, and they need to eat a lot. I dont think that will make them go extinct but for rats used to living in urban environments the absense of people would be a huge problem. It is after all an example of specialisation towards an environment that disappears…
Rats do well in many environments, including some pretty hostile ones such as South Georgia. They breed fast and eat anything. Presumably they do need to eat a lot. The brown rat seems to have evolved to live with us. Other rat species are perhaps not as destructive.
That is why I clarified it is urban rats, those are going to struggle without us, like a lot of urban adapted species and domestic animals. More likely is these urbanised animals will hybridise with more wild close relatives, but the variants that are so widespread in our urban envirnoment will disappear.
Should also be noted that it is not necessarily the first survivor that is most successful after a mass extinction. The P/T saw Lystrosaurus take over the planet in the early Triassic but it went extinct completely only a few milion years later with no descendents. The first large mammals after the K/Pg were very similar, going extinct within 10 million years, and being largely unrelated to any modern group. It is also not unusual for megafauna of the ‘non-dominant’ animal groups to evolve either in these early arms races. Colder world climates will favor mammals, while a warm climate will encourage evolution of larger reptiles too, birds are morphologically restricted from truely megafaunal niches (bipedal, no teeth) so the climate is not particularly advantageous to them either way, not nearly so much as it is between mammals and reptiles. The fact the Earth is broken up into many continents and landmasses will only further encourage diversification too, something in common with the K/Pg but not the case for the P/T or the T/J extinctions.
But rats do seem very human depending eating our trash in cities rats thrive best
Rural rats live a rather poor existence
If humans woud get wipded out then most of the rats goes with I guess
This russia eruption is just a little fart compared to Ionian eruptions like Surt 2001 and later events 10 s of times more thermal energy than Laki even
High Energy Ionian outbursts ( lava fountains) deseves even a separate article from me
Piton de la Fournaise, the french version of Hawaii, increases its seismicity. It could be the next Hot Spot volcano to erupt. https://www.ipgp.fr/volcanoweb/reunion/Bulletins-Communiques/2023/Communiques/OVPF_20230411_11h00_communique.pdf
Cool photo of ash from the Shiveluch eruption after having settled outside of a remote development near the Klyuchevskoy group.
I find this a wonderful photo not only due to the visuals on the ash, but also to get a perspective on the scale of the Klyuchevkoy group. I think the thing that may be most fascinating to me is what looks like very broad and very very large doming going on across the entire complex.
Fantastic! It looks like a centimeter (or two?). VEI-3?
On a telegram post I saw 8.5cm in the town of Kliuchi. I think thats the town in the photo.
Some areas its more.
In the actual telegram channels you can find many more photos and videos.
that could be low to mid VEI-4
Regarding the doming, I am not sure if this is truly doming in the sense that geologists would use it. It could be that this is all volcanic output that has piled up over a long time frame. But I would personally believe it’s probably a mix of both.
With that said, any doming would likely be coming from very deep (25+km) as that is the only known deep source of magma accumulation, whereas shallow magma chambers are not all that large here from the limited information we can see.
The image has quite a bit of wide angle lens distortion, so the visual impression of a doming effect is exaggerated. I think it’s mostly volcanic piles on a horizon that’s curved by the lens distortion.
Yeah, no doubt the lensing effect exaggerates the “doming effect”.
That being said, either the volcanic piles are absolutely massive, or there is a significant amount of doming going on still. You can see this in other images that don’t have the lens distortion, or even just see it from above via Google earth.
Here is a nice visual from the space station:
I always looked at it as the ‘doming’ is just the erosional outwash, presumably the whole thing was thickly glaciated but like in Hawaii most of the evidence of that has been buried. But as you know glaciers have significant outwash fans. And even if not that tall mountaisn tend to get these anyway. Surprisingly I never came to the conclusion it might be actual uplift.
I would presume in reality it is a little bit of doming, but probably still mostly erosion. Also that if there is any doming now, it is not building to a VEI 7-8 but is perhaps a precursor to something like the eruption on Lanzarote, or off the coast of Mayotte, a huge deep source basaltic eruption. 1975 eruption was like this in part, so something that is a couple times bigger is not out of the question I think.
As of yet, probably no really big silicic eruptions, only at Bezymianny, and it is not really evolved to that point yet as a volcano, it isnt a caldera system. But then, basaltic VEI6+ calderas do exist in back arc settings like this so who knows one day 🙂
Maybe in a million years this will be the supervolcano you have hypothesized. Seems a bit of a long process to make these supervolcanoes.
Added to the glacial and fluvial outwash, there are also massive lava flows which have erupted from flank vents of Ushovksy, Tolbachik, and Kliuchevskoy. They form a lava plateau around the volcanoes. Some of the flows of Ushovsky are really gigantic, aa lava shields, and form a massive lava apron around the volcano. If I had to guess, then some of these lava flows have multiple cubic kilometres.
I like this place to appreciate such things:
Of course there could be a hidden uplift, but that could be said for almost any volcanic complex.
They make other Kamchatkan stratovolcanoes look insignificant, even though some of the other Kamchatkan volcanoes are already bigger than average:
Chad, I agree.
I don’t think this is anywhere close to what you would see with a VEI-8 eruptor in the near geological future. I do think over a much longer time period, conditions could evolve where this could become a supereruptor due to the uniquely prolific input and the tectonic setting. But if that’s the case, it’s at the earlier stages of that long life-cycle.
Klyuchevskoy basically doesn’t even have a proper magma storage chamber with it being fed fresh basalt from the moho. The younger volcanoes are more similar to Klyu, whereas the older ones seem to show a progressive evolution to have gained the more silicic intermediate storage chambers. I believe that is where Klyuchevskoy is heading eventually, but since it’s so young, intermediate depth magma storage zones are just starting to develop and form.
A while back, I wasn’t sure if there was larger, intermediate depth magma being stored beneath this complex that could be silicic, but based on the academic literature I’ve read since then, it seems that the only silicic magma chambers are still unique to each individual volcano in the grouping, and for the more basaltic ones, they don’t really have any noteworthy chambers at all. Given, they all are connected from a deep source around the moho, which if there was doming, I would assume would be the source for that.
And thanks for sharing that image Hector, that gives a good view into why I’m so wowed by the scale of the volcanism here.
It’s one of those things where if you consider these all independent volcanoes in isolation, they are large, but maybe nothing special. But when you consider that they’re all potentially a product of the same system, the scale is on a very unique level.
Some of the unique features that likely contribute to the prolific nature here include:
– Potential inclusion of subducted portions of the emperor seamount
– Likely slab gap causing an increase in the upwelling and magmatic input
– Lithospheric thinning
Overall, I think the biggest reason this region may never reach a VEI-8 potential is that it seems that the “roof” material simply isn’t strong enough to form large scale magma chambers. Based on what can be observed, magma tends to find it’s way up and to the surface with relative ease in this region, hence why Klyuchevskoy is basically a 30km tube being fed directly from the Moho. And why Tobalchick is basically just a series of sills and dikes. That can change and evolve on a very long time frame, and the more that material is emitted above the region, the stronger that any potential lid will become. This is already what likely happened at Ushkovsky, where the paths to the surface for the magma became too plugged up, so the deep source found a new easier path to the surface, which gave us what is now Klyuchevskoy.
Regarding ‘hidden uplift,’ I always wondered how we account for uplift that occurred at systems prior to the satellite era. It’s but a paltry number of years that we’ve been monitoring active volcanic systems with modern instrumentation to observe uplift in real time, do geologists have any methods to reasonably determine uplift that initiated prior to direct observation?
Theoretically couldn’t there be systems primed and ready to go with massive uplift from the recent geologic past, but it’s invisible to us as perhaps that uplift stabilized prior to satellites going up? Or even just that we’re only catching that which occurred since and not everything prior?
Large earthquake in the Java Sea. It is close to Bawean Island. Very deep
I’ll post faster next time, mark my words.
Crazy 600 km deep M 7 quake at Indonesia today. Minimal damage
I can’t believe this but Aniakchak is uplifting at the mind-boggling speed of 3-4 cm per WEEK! magma is probably intruding into the shallow reservoir at 3-4 km at depth and with modest seismic activity an eruption isn’t imminent. But CCN is going to have to step up it’s game if it want’s to keep my attention.
That would be almost 2 meters in a year. It’s really fast. Not even basaltic calderas are inflating at that rate. Makes even Laguna del Maule look bad. It remains to be seen how long it will last though.
Will be interesting if it erupts the same as it did in 1937. Maybe we will get to see a dacitic curtain of fire 🙂
Chiles-Cerro Negro, another volcano that’s under some unrest as of late,
CCN is currently undergoing it’s 4th major seismic swarm now and while something is definitely off about this volcano, I am getting tired of the small escalations at the system and want something more dramatic which Aniakchak is providing so far. Hopefully we get something interesting this year.
Don’t lose faith! CCN is playing the long game IMO.
It’s building to …something. The unrest has been too consistent over too long a time, IMHO I think we’ll eventually get some fireworks, whether soon or in a decade or two (granted the wait would be difficult).
Of course I can’t say what the eventual eruption will be like, could be an effusive silicic event as Chad has mentioned. But either way and regardless of the style, a long, long dormant system waking up and erupting will be remarkably fascinating either way!
I am full of expectations for CCN, the volcano just doesn’t quit! Over a million earthquakes in just under 10 years and still going strong. We don’t know what’s causing the current swarm but it is pretty erratic. The IGEPN has stopped publishing regular comprehensive monthly reports, the last one released was for May 2022. It is strange considering the intensity of the 2022 swarm and what caused it. No gps data or explanations.
Simulation of the Hunga Tonga tsunami
“Volcanic Eruptions can’t produce long distance tsunamis…” Garbage assumption! Absolutely garbage assumption! “Extra-tropical volcanoes can’t produce intense volcanic winter like tropical eruptions.” It is amazing how these unfounded propositions became popular and were treated like fact for so long when there was NO supporting evidence. And I bet that some of the same people who supported these wholly debunked ideas are going to act like they weren’t wrong for years.
There were reasons for those assumptions. Volcanoes are point sources, while faults are long lines. The thought was that long distance tsunamis require lines because in that case the tsunami does not decline as much over long distance. And this did hold up for Hunga Tonga which had a large tsunami at 100 km but ‘only’ 1-2 meters at 1000+ kilometers. It could have been much worse with Japan swamped by a 5 meter tsunami instead.
What data was that assumption based on? All of the volcanic tsunamis of late were the result of an inferior injection in comparison to earthquakes. All tsunamis are the result of an injection of energy into a body of water resulting in displacement. The Tonga eruption displaced less water and injected less energy than the 2011 earthquakes but produced a larger initial wave. The energy was more concentrated and produced larger tsunami initially but the wave lost steam quicker than an earthquake-generated tsunami. Models have shown and supported long distance tsunamis from volcanic eruptions this whole time but were largely ignored.
It was based on physics. The wave from a point source (eruption) declines linearly with distance (at least until curvature of the Earth becomes important) while the wave from a long line (earthquake fault) stays constant until it is further away than the fault was long. That held pretty well for Hunga Tonga. But of course it started out as a humongous 100-meter wave while for instance the 2004 tsunami started as a 30-meter one. It probably wasn’t realized how large a volcanic wave can be at the origin. We were extremely lucky. Hunga Tonga could easily have wiped out the entire Tonga region. The main wave was directed away from the populous islands.
The reason why the Tonga tsunami was so large initially was because it came from a point source. That should’ve been expected. Scientific models have long predicted long distance tsunamis from single point sources and while earthquakes have a far easier time producing long distance tsunamis by no means did it mean that long distance volcanic tsunami were impossible The sample size for historical volcanic tsunamis in the past 100 years is pathetic and there was no volcanic event that displaced as much water an earthquakes in the past century because all of the recent volcanic tsunamis were the result of small landslides and small pyroclastic flows. Wholly incomparable to M 8-9 earthquakes but people compared them nonetheless and used the weak volcanic tsunamis to justify this proposition
Thing is Hunga Tonga may not have been a point source:
Interestingly I saw that the article mentions the 1956 eruption of Bezymianny as making a meteorological tsunami too, which I wasn’t aware of. This eruption also produced a powerful atmospheric wave, due to the intensity of this lateral blast eruption. Doing a bit of search I found this:
“One of the greatest explosive eruptions in the present century was that of Bezymianny. For the details see Gorshkow (1959). At the time of the paroxysmal eruption a relatively small tsunami with a tsunami magnitude of
around 0 was observed (Iida et al. 1972). The maximum height of the wave was as small as 0.3 m at Attu, in the Aleutians. At the time of the tsunami’s origin no tectonic shocks occurred (Rothe 1969; Regional
Catalogue of Earthquakes, 1956, International Seismological Centre, Edinburgh). Therefore, it is concluded (Hedervari 1980) that the tsunami was
generated by the air waves of the explosion, similar to the case of Krakatau (see No. 218 in Hedervari 1984) where many smaller waves were observed very far from the volcano and were recently attributed to airsea interactions. Thus, Bezymiaany represents the second example for such events.”
Yes, meteotsunamis are clearly important. By the way, Tambora also created one which the Bezymiany paper overlooked. ‘point source’ relates to the fact that the energy originates in a small region. The decay with distance should be the same regardless whether the wave travels by sea or by air. Once the wave has traveled more than 8000km or so, it stops declining – from that point onward, all tsunamis should continue similarly. Hunga Tonga (and presumably Krakatoa as well) was extremely efficient in putting its energy in water and air waves. Major earthquakes deposit most in the crust. So Tallis has a point that an eruption does not have to be as large as an earthquake to generate a similar tsunami, at least when it is in shallow water. It should be noted that this was the largest such explosion in almost 150 years. In that tie we have had a series of tsunamis that were much larger. The dominant danger for major tsunamis remains subduction earthquakes
Bezymianny was a horizontal shock wave. Like St. Helens 1980 or Pelee 1902.
Honga Tonga was a circular shock wave equally towards all cardinal directions. The explosion force was weaker concentrated.
As far as I can tell, Hunga Tonga was a meteo-tsunami, caused by the pressure variations in the atmosphere. I was already aware of Krakatau’s meteo-tsunami when the Tonga eruption happened. And Hunga Tonga fit very well within my expectations of how it would look like.
One additional way to preserve fossils over a long time are caldera lakes and maars. A famous example of Eocene is the Messel Pit Fossile Site close to Frankfurt in the Upper Rhine Valley. There a maar lake became the cemetry of mammals and other species during that time. https://whc.unesco.org/en/list/720
Messel quarry is an ancient maar, filled in over time with sediment that has yielded all of the fossils. It is fascinating how this site is only 120 km away from Laacher See, which is probably where the word maar was first applied in to context of referring to a volcano. Only an hour drive (maybe a half hour there 🙂 ) away but 50 million years apart in time
The best fossils of them all is Messel Pit too insane detail from the fine grained oil muds. PETM enviroments fossile poorly because they where so hot and humid, only anoxic lakes may yeild tropical rainforest fossils, and thats why modern hardwood tropical rainforests have a very unknown evolutionary origin because they done fossilize well. 🙂 But at least in Early Eocene modern rainforests where already global
There may have happened more maar eruptions during the Eocene, but subsidence in the Upper Rhine valley put them down below the surface. Sediments hide much. There was a rifting strait like Bosporus from Thetys over Upper Rhine valley and Weser to present North Sea area.
The “volcano age” in this region came later during Oligocene and Miocene. For this the maar in Messel was supposedly part of many precursors. During Ice Age the volcanism migrated to the west over “Westerwald” to Eifel which had its last three eruptions (two maars and one caldera eruption) around 10-12 thousand years ago.
Thanks for the link! Extremely interesting!
Aftermath at Sheveluch:
Blown away by pent up gassy magma
Peleean style blast
Hardly Jesperian in scale but at least something
Starship launches soon
New post is up! Phantoms of the sea
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