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women of note 1: Mary Anning, palaeontologist

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She sells sea-shells on the sea-shore,
The shells she sells are sea-shells, I’m sure
For if she sells sea-shells on the sea-shore
Then I’m sure she sells sea-shore shells. 

Terry Sullivan, 1908 – said to be inspired by Mary Anning’s fossickings

Unfortunately, I want to write about everything.

So now I begin an occasional series about women to be celebrated and never forgotten.

Mary Anning was born in the seaside town of Lyme Regis, Devon, in 1799 and died there, too young, of breast cancer in 1847. According to Brian Ford, author of Too big to walk: the new science of dinosaurs, she was ‘the first full-time professional palaeontologist anywhere in the world’. It’s a fair statement; those before her were generalists, given the name ‘naturalists’, and made their livings as pastors or physicians, or were independently wealthy. The term ‘palaeontology’ was just starting to gain traction in the early nineteenth century, replacing the intriguing but probably short-lived ‘oryctology’, though fossil-finding and speculations thereon (mostly infused with religious or mystic beliefs) date back to civilisation’s dawn.

Fossil-hunting had become quite trendy from the late eighteenth century, and Mary’s dad, a cabinet-maker by trade, supplemented his income by selling fossil bits and pieces, discovered himself on the nearby cliffs, to locals and tourists (the region had become something of a haven for those escaping the Napoleonic wars). The cliffs around Lyme Regis on England’s south coast form part of the Blue Lias, alternating sediments of shale and limestone, very rich in fossils from the early Jurassic, around 200 mya.

Richard and Molly, Mary’s parents, had ten children, but only two, Joseph and Mary, survived infancy. Childhood diseases such as measles were often killers, especially among the poor – a reminder of how lucky we are to be living in an economically developed country in the 21st century. The Anning family was never well-off, and Richard died when Mary was just 11 years old. Mary herself just managed to escape death by lightning strike when she was a baby. The strike killed three women, one of whom was tending her at the time. But the family suffered many hardships besides infant mortality. Food shortages and rising prices led to riots in the neighbourhood, and Richard himself was involved in organising protests.

As kids, Joseph and Mary sometimes accompanied their father on fossil-hunting trips on the dangerous cliffs, which were subject to landslides. They would sell their finds, which were mostly of invertebrate fossils such as ammonite and belemnite shells, in front of their home, but clearly life would’ve been a real struggle in the years following Richard’s death, during which time they relied partly on charity. It wasn’t long, though, before Mary’s expertise in finding and identifying fossils and her anatomical know-how came to the attention of well-heeled fossickers in the region. In the early 1820s a professional collector, Thomas Birch, who’d come to know the family and to admire Mary’s skills in particular, decided to auction off his own collection to help support them. This further enhanced their reputation, and Mary became something of a local celebrity, reported on in the local papers:

This persevering female has for years gone daily in search of fossil remains of importance at every tide, for many miles under the hanging cliffs at Lyme, whose fallen masses are her immediate object, as they alone contain these valuable relics of a former world, which must be snatched at the moment of their fall, at the continual risk of being crushed by the half-suspended fragments they leave behind, or be left to be destroyed by the returning tide: – to her exertions we owe nearly all the fine specimens of ichthyosauri of the great collections.

Bristol Mirror, 1823 – quoted in Too big to walk, by Brian Ford, p61

As this article mentions, Mary Anning’s name is often associated with ichthyosaur fossils, but she also discovered the first plesiosaur, the identity of which was confirmed by Georges Cuvier – though he at first accused her of fraud. Amongst other contributions, she was the first to recognise that the conical ‘bezoar stones’ found around the cliffs of Lyme were in fact fossilised faeces of ichthyosaurs and plesiosaurs.

plesiosaur skeleton, beautifully sketched by Mary Anning

For my information, ichthyosaurs were marine reptiles dated from the early Triassic to the late Cretaceous periods (250-90 mya), though most abundant in the early period, after which they were superseded as the top marine predators by the plesiosaurs (approx 204-66 mya).

Anning’s exact contribution to palaeontology is impossible to determine, because so many of her finds were snapped up by professional collectors, in an era when attributions weren’t preserved with much care, and this would have been compounded by her status as an ‘uneducated’ amateur, and a woman. Contemporary commentary about her expertise was often infused with a subtle condescension. There’s little doubt that, had she been male, her admirers would have seen to it that her talents were sufficiently recompensed with scholarships, senior university posts, and membership of the prominent scientific societies. Instead, she remained a fixture at Lyme Regis – there’s no indication that she ever travelled, apart from at least one trip to London, though her expertise was recognised throughout Europe and America. It’s also likely that, coming from a family of Dissenters – a reformist Protestant group – she was regarded with suspicion by the Anglican-dominated scientific hierarchy of the time. Let’s take a look, for comparison, at some of the males she associated with, and who associated with her, and how their professional lives went:

Sir Henry de La Beche – KCB, FRS. That first TLA means ‘Knight Commander of the Bath’ or something similar. I seem to recall bestowing a similar title upon myself while commanding battleships in the bathtub at age six or so. Never received a stipend for it though. FRS means Fellow of the Royal Society of course. Son of a slave-owner who died young, Beche was brought up in Lyme Regis where he became a friend of Anning, sharing her interest in geological strata and what they contained. It’s not unlikely that she was an inspiration for him. He was able to join the male-only London Geological Society at age 21, and later became its President. He became a FRS in 1819 at the still tender age of 24. He was appointed director of the Geological Survey of Great Britain in the 1830s and later the first director of the Museum of Practical Geology in London (now part of the Natural History Museum). He was knighted for his genuine contributions to geology in 1848. Beche was in fact an excellent practical and skeptical scientist who gave support to Anning both financially and in his published work.

William Conybeare – FRS. Born into a family of ‘divines’ (at least on the male side) Conybeare became a vicar himself, and a typical clergyman-naturalist, with particular interests in palaeontology and geology. Educated at the elite (and all-male) Westminster School and at all-male Oxford University, after which he travelled widely through the country and on the Continent (all paid for by ‘a generous inheritance’) in pursuit of geological and palaeontological nourishment. He became an early member of the Geological Society, where he met and advised other notables such as Adam Sedgwick and William Buckland, and contributed papers, including one with Beche which summarised findings about ichthyosaurs and the possibility of another species among them, the plesiosaur. This was confirmed by Anning’s discovery and detailed description of a plesiosaur, which Conybeare later reported to the Geological Society, delighted to be proved correct. He failed to mention Anning’s name. In 1839 Conybeare, together with two other naturalist heavyweights, William Buckland and Richard Owen, joined Mary Anning for a fossil-hunting excursion. Unfortunately we have no smartphone recordings of that intriguing event.

William Buckland, DD [Doctor of Divinity], FRS. Born and raised in Devon, Buckland accompanied his clergyman dad on walks in the region where he collected fossil ammonite shells. He was educated at another elite institution, Winchester College, where he won a scholarship to Oxford. In 1813 he was appointed reader in minerology there, and gave popular lectures with emphasis on geology and palaeontology. He seemed to cultivate eccentricities, including doing field-work in his academic gown and attempting to eat his way though the animal kingdom. His most important association with Mary Anning was his coining of the term ‘coprolite’ based on Anning’s observation that these conical deposits, found in the abdomens of ichthyosaurs, were full of small skeletons. Clearly, Anning knew exactly what they were, but had no real opportunity to expatiate on them in a public forum. Women were often barred from attending meetings of these proliferating scientific societies even as guests, let alone presenting papers at them.

Gideon Mantell, MRCS [Member of the Royal College of Surgeons], FRS. Mantell was himself a rather tragic figure, whose association with Anning was less personal, though he did visit her once at her Lyme Regis shop. He was inspired more by news of her ichthyosaur discoveries, which reinforced an obsession with fossil hunting in his own region of Sussex, where many fossils of the lower Cretaceous were uncovered. Born in Lewes in Sussex, the fifth child of a shoemaker, he was barred from the local schools due to his family’s Methodism. He underwent a period of rather eccentric but obviously effective private tuition before becoming apprenticed to a local surgeon. Though worked very hard, he taught himself anatomy in his free time, and wrote a book on anatomy and the circulation of the blood. He travelled to London for more formal education and obtained a diploma from the Royal College of Surgeons in 1811. Returning to Lewes, he partnered with his former employer in treating victims of cholera, smallpox and typhoid epidemics, and delivering large quantities of babies, building up a thriving practice, but also somehow finding time for fossil-hunting, corresponding with others on fossils and geology, and writing his first paper on the fossils of the region. He started finding large and unusual bones and teeth, which turned out to be those of an Iguanadon, though it took a long time for this to be recognised, and he was mocked for his claims by experts such as William Buckland and Richard Owen. Although he was becoming recognised for his many writings and discoveries, he always remained something of an outsider to the establishment. He later fell on hard times and suffered a serious spinal injury from a horse-and-carriage accident, from which he never really recovered. He apparently died from an overdose of laudanum, used regularly as a pain-killer in those days.

Returning to Mary Anning, we see that class as well as sex was a barrier to intellectual acceptance in early nineteenth century Britain – but sex especially. Mary struggled on in Lyme Regis, recognised and sought out by other experts, but never given her full due. In the 1840s she was occasionally seen to be staggering about, as if drunk. In fact, she too was dosing herself on laudanum, due to the pain of advancing breast cancer. She died in 1847, aged 47.

I should point out that, though Mary Anning’s name is largely unknown to the general public, so are the male names mentioned in this article. We generally don’t fête our scientists very much, though they’re the ones that really change our world, and help us to understand it. Mary was helped out by luminaries such as Beche and Buckland in her later years, and received a small annuity from the British Association for the Advancement of Science. Upon her death, Beche wrote a modest eulogy, which he presented at a Geological Society meeting, which, had she been alive, Anning wouldn’t have been allowed to attend. It was later published in the transactions of the Society. Here’s how it begins:

 I cannot close this notice of our losses by death without adverting to that of one, who though not placed among even the easier classes of society, but one who had to earn her daily bread by her labour, yet contributed by her talents and untiring researches in no small degree to our knowledge of the great Enalio-Saurians [now known as Euryapsida], and other forms of organic life entombed in the vicinity of Lyme Regis ..

Mary Anning by her beloved cliffs, tool in hand, pointing to her not yet dead dog Tray, killed in the line of scientific duty…

References

https://en.wikipedia.org/wiki/Mary_Anning

https://ucmp.berkeley.edu/history/anning.html

https://www.nhm.ac.uk/discover/mary-anning-unsung-hero.html

https://www.britannica.com/biography/Mary-Anning

https://en.wikipedia.org/wiki/Ichthyosaur

https://en.wikipedia.org/wiki/Plesiosauria

https://www.bgs.ac.uk/discoveringGeology/time/Fossilfocus/ammonite.html

https://www.bgs.ac.uk/discoveringGeology/time/Fossilfocus/Belemnite.html

https://www.britannica.com/biography/Henry-Thomas-De-La-Beche

https://en.wikipedia.org/wiki/Henry_De_la_Beche

https://en.wikipedia.org/wiki/William_Conybeare_(geologist)

https://www.strangescience.net/conybeare.htm

https://en.wikipedia.org/wiki/William_Buckland

https://www.theguardian.com/science/2019/feb/03/gideon-mantell-play-fight-over-first-dinosaur

https://en.wikipedia.org/wiki/Gideon_Mantell

Written by stewart henderson

September 24, 2019 at 11:14 am

Earth before life: more skeptico-romantic chitchat

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The early Earth - more cracks than facade?

The early Earth – more cracks than facade?

Canto: So we’ve talked all too briefly about Earth’s probable formation and how its moon was formed some fifty million years later, and I’m not sure whether I want to go back further in time to try to answer some big questions about the solar system in general or the solar nebula, or forward to consider how life emerged from inanimate matter on this seething-hot, volatile planetary surface…

Jacinta: Well since we’re the blind leading the blind, it doesn’t much matter which direction we go. Let’s choose life.

Canto: Okay, but we’ll have a way to travel before we get there.

Jacinta: Well most of us learned at school that the Earth has a crust, a mantle and a core, and that the core is of iron and it’s really hot down there, and the crust is formed of plates that move around and go under each other, and that the atmosphere above the crust consists of layers, like the stratosphere and the ionosphere, and the atmosphere around us is around three-quarters nitrogen and a quarter oxygen with traces of other gases, and if it wasn’t like that we wouldn’t be here. But it wasn’t anything like that when the first life appeared.

Canto: Yes, it was very different, and it seems there’s more that we don’t know about the period between 4.5 and 4 billion BP than there is that we do know, if you know what I mean.

Jacinta: BP?

Canto: Before the Present. I got that from the excellent Stuff You Should Know podcast, and I’m going to use it from now on.

Jacinta: D’accord. So yes, we know that the early Earth was incredibly hot, reaching temperatures of 2000 celsius or more, but there’s also evidence from ancient amphibolite rocks and banded iron formations that there was water on the Earth, and plenty of it, 4.3 billion years ago. Which suggests an extraordinarily fast cooling down period, and where did all that water come from?

Canto: Yes I think we really need to look at this period, or what we know of it, to try and make sense of it, because it doesn’t quite make sense to me. A hot magma world, melted fom the inside out, but also bombarded from the outside by meteorites, then after the bombardment suddenly cooling from the outside in, and flowing with water. All in a couple of hundred million years?

Really?

Really?

Jacinta: That’s a long time actually. We’re hoping to live for a hundred years for some strange reason – a two millionth of our time-frame, if we’re very lucky.

Canto: Well it’s all relative, but where did this water come from? Some say it must’ve come from space, because that’s all that happened, meteors from out there crashing into here. Where else could it come from?

 

Jacinta: How do you trap water here when the surface temperature is so high? Water boils at 100c, right?

Canto: Under ‘normal’ atmospheric pressure. The early Earth was anything but normal.

Jacinta: Anyway it just doesn’t seem possible to get so much water from rocks crashing into us. There’s another alternative – the water was already here. So the original bits and pieces that formed the Earth – carbonaceous chondrites or whatever – contained water and this water somehow made its way to the surface.

Canto: Somehow. Leaving aside the rising-to-the-surface problem, carbon-rich chondrites are found in asteroids today, and they have apparently a similar water-plus-impurities ratio to our oceanic water, and that’s obviously very suggestive.

Jacinta: Yes and the isotopic ratios pretty well match, but they don’t for comets. Scientists have been able to measure the isotopic ratios in comets such as Halley and Hale-Bopp, and they don’t have anything like the proportions found in our oceans. I’m talking heavy water here, deuterium, but also protium which is another isotope of hydrogen.

Canto: NASA also launched a spacecraft, Deep Impact, to probe the constituents of a comet, Tempel1, and the results were negatory for its candidature as feeder of the Earth’s water, had it ever landed here, but of course not nugatory for astronomical research generally. But then, what comet is ever typical? Anyway, there’s a just-so story, sort of, that I watched on video recently, which explained the oceans, sort of. It told us that the planetesimals that created the Earth contained water locked inside, and that years of later volcanic activity released that water to the surface as steam, which condensed in the cool upper atmosphere and fell as rain. And the rain it rainèd every day.

Jacinta: So the Bible was right then?

Canto: More than forty days and nights – thousands of years, they claimed. But that made up only half the world’s oceans. The rest came from comets, they said. Now that seems unlikely, but replace comets with the right sorts of asteroids, and the recipe still works.

Jacinta: Well here’s another story, which is meant to explain how that heat-creating heavy bombardment came to an end.  The Earth’s bombarded surface was extremely hot, melting everything, even the rocks, and in this state the heavier elements such as iron sank to the centre, forming our core, which was vital in protecting us from the notorious solar wind – that incredibly strong force that has blown away the atmosphere of Mars.

Canto: Yeah, they say it kind of magnetised the Earth, and that was like a shield of steel.

Jacinta: Aka the magnetosphere, but I’m afraid that electromagnetism was a subject that transformed me into a gibbering mass of incomprehension at school.

image

Canto: I can’t say I understand it myself, but the magnetosphere works to almost perfectly preserve our atmosphere. We do lose a percentage to the solar wind every year but it’s so tiny that it’s not a problem. Another anthropic circumstance that proves the existence of God.

Jacinta: Hallelujah. So did this magnetosphere form before or after the formation of the moon?

Canto: God knows.

Jacinta: Goddess.

Canto: Sorry princess.

Jacinta: Princess, goddess, actress, countess, diminutives. They diminish.

Canto: Seamstress.

Jacinta: Temptress.

Canto: Watercress. Anyway it probably happened around the same time. The great crash that probably created the moon has been nicely computer-simulated by Robin Canup of the Southwest Research Institute – it’s well worth a look. The theory goes that this great glancing blow tilted the Earth and gave us our seasons, probably vital to life as we know and love it.

Jacinta: Yes but it would’ve heated up the planet even more, so I’m interested in the problem of the shift from this to our amphibolite rocks under water from nearly 4.3 billion years ago. Where the eff did that water come from? It steamed up from beneath the surface? Not likely. And from asteroids? Really?

Canto: Possibly. But according to this excellent Naked Science video, the best-preserved meteorites ever recovered came from a landfall in British Columbia in 2000. And when they investigated this meteorite material they found that it was made up of 20% water by weight, and that’s pretty significant…

Jacinta: Because water isn’t dense like rock is it, so that sounds like a lot of water. We’re learning a lot from this video, such as that meteorites don’t cause great fireballs or anything like that, because they’ve been tumbling about in cold space for eons, and their entry into the Earth’s atmosphere only heats up a few millimetres of the outer surface, and then only for a very brief period, so they pretty well instantly go cold again.

Canto: Right and maybe that explains something else; that a heavy bombardment of these big wet boulders – and apparently they’ve found that the further they are from us, the more water they contain – would’ve cooled the planet.

Jacinta: Interesting idea, which I’m sure someone’s thought of and maybe even computer modelled. Certainly it would help to explain the apparent speed with which the oceans were formed. So… I’m not really convinced, but in lieu of a better explanation I’ll take it on trust that the oceans were created in little more than a million years or so by a hailstorm of asteroids, together with water steamed up from below the surface. So now we have a somewhat cooler Earth, ready at last for some kind of life, but not as we experience it.

Canto: Right, we’re talking about an atmosphere containing virtually no oxygen. Made up mostly of nitrogen, carbon dioxide and methane.

Jacinta: And how do they know that? I’ve also heard hydrogen sulphide mentioned.

Canto: Yeah, upwellings from volcanic activity I believe.

image

Jacinta: So the stage is set for some sort of proto-life, with RNA or some precursor. And so the fun begins, if it hasn’t already.

Canto: Indeed it does. So that’s what we’ll be exploring next. I’ve even heard some researchers claim that water isn’t necessary for basic life to get started. Now there’s heresy for you.

Jacinta: That’s the fun of heresy these days, you don’t get burned alive for it, no more than a bit of gentle ribbing. I’m looking forward to the next post.

Written by stewart henderson

July 21, 2016 at 9:34 pm

some local geology: granite and glaciers

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victor_harbor_17_march_2007_20070317_002

a bunch of granite dumped on Granite Island

While at Victor Harbour, we did the usual walk around Granite Island, marveling at these massive lichen-covered granite boulders and reading the signs about their origins, and their hardness and consequent permanence, compared to, say, limestone.
Granite is a composite of 3 minerals – quartz (bluish), feldspar (pink and white) and mica (black biotite). On the island it’s found in great heaps of rocks, called xenoliths, subject to weathering known as tafoni – though the examples there aren’t spectacular, compared to others, such as Kangaroo Island’s Remarkable Rocks. This granite has upwelled from – well, somewhere – back in the Cambrian, about 520 million years ago. Granite is igneous rock, generally formed from molten lava under the surface which slowly pushes its way through cracks and spaces to just below the surface, over millions of years, where it’s finally revealed through soil erosion – at least that’s the story I’m getting through my reading. What I see, though, is a mixture – boulders in heaps, at the tops of hills, that look like they’ve rained down from the sky; great cliff faces that look more like upwellings; and, in gullies, a combo of large and small boulders that look the end-product of an avalanche.
Well, a lot can happen in 500 million years, but I’ll try to make sense of it, not only for Granite Island but the region around it. Here’s an intro from the geological society of Australia:

Grey metamorphic rocks are exposed in natural outcrops, road cuttings and along the sea coast over much of southern Fleurieu Peninsula and Kangaroo Island.
They are called the Kanmantoo Group by geologists and were deposited into a rapidly subsiding ocean basin as fine grained sand and silt eroded from large land masses to the west and south in the Cambrian Period about 520 million years ago.
After the basin filled, this sequence of sediments was buried deeply below the earth’s surface and altered (metamorphosed) by heat and pressure into their present form. They were also intruded by masses of molten granite (called the Encounter Bay Granite) and were then thrust up into a mountain range in a major earthmoving event called the Delamerian Orogeny which ended about 475 million years ago.

So it would seem that the Delamerian Orogeny was responsible for the granite formations on Granite Island and thereabouts. They were igneous intrusions resulting from the uplift and folding of the lithosphere (the earth’s crust and mantle) due to the clash of tectonic plates (the meaning of orogeny). This particular orogeny, occurring at the end of the Cambrian period and into the Ordovician, created the Flinders and Mount Lofty Ranges (the Adelaide geosyncline). In those days, the area was part of the supercontinent called Gondwana – in fact the Delamerian was one of several orogenies that contributed to its formation.
Fast forward a few hundred million years, to the Paleozoic era, and Gondwana was located around the South Pole, though parts of it extended almost to the equator. In those days the highlands of the Adelaide geosyncline, which had eroded down over the years, were often covered in ice caps, though the planet overall was warmer than today. Geologists find evidence of glacial activity from that period, from Port Elliot round to Hallet Cove:

Boulders of Encounter Bay Granite and Kanmantoo Group rocks, plucked off the surface and moved many kilometres by the ice from their original location, are a common feature of this glacial terrain. They are called erratics.

There’s so much more to explore in this line, obviously, and it’s a perfect example of a little scratching at the surface of a subject revealing, for me, a whole world of ‘known unknowns’, to quote the immortal Donald Rumsfeld. Science is amazing in its accumulations from researchers across the globe. So now, when I see strange boulders in out of the way places and unrelated, apparently, to the rocks around them, I’ll think of glaciation and erratics as a possible explanation.

2012.06.04_Auswick Norber erratics

Written by stewart henderson

February 8, 2014 at 9:41 am

Posted in geology

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