Thursday 23 December 2021

Inside a Dinosaur Egg

Inside a Dinosaur Egg 

THIS ARTICLE describes what you see if you happen to have a dinosaur egg hanging about your museum for fifteen years (and are the curator of Yingliang Stone Nature history Museum). Yes the curator noticed some bones poking out of a slightly damaged dinosaur egg. He had a fossil preparator work on the egg and found this!


The oviraptorosaur embryo ‘Baby Yingliang’ provides a rare glimpse into the prehatching behaviour of non-avian dinosaurs. Xing et al., 2021, Author provided

It is an Oviraptosaur embryo and now palaeontologists have a new vocabulary to learn. They have to familiarise themselves in the development of birds inside an egg as this fossil shows that dinosaurs (at least this species) seem to show all the characteristics of hatching birds! 

This is a very interesting article and is worth reading. The wonderful preservation of these specimens from China is breathtaking!

Wednesday 22 December 2021

Asteroid Ryugu and the Early Solar System

Asteroid Ryugu and the Early Solar System 

A few weeks ago I reported on the results of ANOTHER ASTEROID ENCOUNTER.

THIS ARTICLE reports on another one! It concerns the asteroid Ryugu. The encounter collected almost 5.5g of material. The asteroid is rich in carbon and water and this type of asteroid may be the source of carbonaceous chondrites meteorites. 

The recovered material is not as dense as the meteorites but then it has not gone through a fiery entry through the Earths atmosphere. Therefore the material may contain components which are not found in the meteorites.

And that component may be nitrogen from ammonium-bearing clay minerals or nitrogen-rich organic material. Further information is eagerly anticipated!


 
Image of Ryugu taken by the Hayabusa 2 spacecraft in 2018. JAXA/wikipedia, CC BY-SA

Tuesday 14 December 2021

What's Inside an Ammonite

What's Inside an Ammonite 

A correspondent sent me THIS LINK which tells us about new research into ammonites. If you have access you can read the source paper HERE.

The article records the use of X-ray tomography (a non-destructive technique) on an exceptionally well preserved ammonite from Gloucestershire, which is in the National Museum of Wales. It was found 20 years ago. It could have been opened up then, but it was kept until modern methods allowed it to be studied without breaking it.


Backlit shell with visible organs (to the left)


Left: 3D reconstruction. Right: Labelled internal organs

The results are that the animal is believed to have moved by jet propulsion, like many cephalopods and that it had paired muscles which could retract the beast inside its shell.

This is unlike Nautilus which has been used as a modern analogue of ammonites.

Saturday 11 December 2021

Battle Axe Dinosaur

Battle Axe Dinosaur 

A correspondent has sent me A LINK to an article in the New York Times. I am not sure whether this will work indefinitely but give it a go and let me know. The article is based on a paper in Nature. You can see an abstract HERE.

The remains of the beast were found in sub Antarctic Chile and is a species of the ankylosaurs, who are known for their heavy armour. This individual has been named as Stegouros elengassen and has an unusually shaped tail. It looks somewhat like a macuahuitl - a Mesoamerican club edged with obsidian. And a sort of battle axe!



An artist’s reconstruction of a new species of armored dinosaur discovered in southern Chile, Stegouros elengassen.Credit...Luis Pérez López




Digital reconstruction of the unique tail weapon of the new species of armored dinosaur Stegouros elengassen. The tail was encased in pairs of dermal bones; a portion of the dermal bones has been digitally sliced away, to reveal the tail vertebrae within. Different colors signal physically separate bones; many dermal bones have fused into a single unit (liliac).CreditCredit...José Palma and Joao Francisco Botelho

3 Publications

 3 Publications

Three publications have come my way. They are:
  • Geo Conservation Newsletter. You can get it HERE or read it below.

  • Herefordshire and Worcestershire Earth Heritage Trust news update. You can get it HERE or read it below.

  • A poster from West Midlands Regional Group of the Geological Society detailing everything geological in the West Midlands. With Zoom lectures proliferating much on the poster is available to everyone, You can get it HERE or read it below.

Friday 3 December 2021

Mountain Building Needs Plankton!

Mountain Building Needs Plankton! 

THIS ARTICLE based on THIS PAPER tells us that without organic carbon in the form of graphite, mountain building would not have taken place. Organic carbon became possible after the Great Oxidation Event at c. 2.3 Ga and there are few mountain building episodes before this. The graphite provided the necessary lubrication.

Timeline for the formation of mountains on Earth. J Johnston/University of Aberdeen, Author provided


The academic paper goes through many mountain building episodes and in each of them finds carbonaceous sediments involved in all of them.

The article is well worth reading and the academic paper gives a great deal of information - interesting stuff!

Thursday 2 December 2021

Does Half Our Water Come from the Sun?

Does Half Our Water Come from the Sun?

Remember the Japanese mission to get a piece of an asteroid? It happened in 2011 and work is still being done on the samples returned. THIS ARTICLE records what one team discovered on some tiny particles of the asteroid. The article is based on THIS ACADEMIC PAPER which has not yet been fully published.

Using atom probe tomography they found that the surface of the particles was rich in hydroxide (OH), and much more surprisingly water molecules (H₂O).

The most likely source of the hydrogen atoms is the solar wind which consists of hydrogen ions. The conducted experiments to prove this was possible.

And their conclusion was that half of the Earths water came from this source in the time that the Earth was forming - there were lots of asteroidy things basking in the suns light at this time. And this would explain the isotopic composition of the Earth's water which is otherwise difficult to understand.


The asteroid Itokawa was the source of grains of dust which contained a surprising layer of water. JAXA

Tuesday 16 November 2021

Deep Mantle Mineral Found in Diamond

Deep Mantle Mineral Found in Diamond 

THIS ARTICLE tells us of a newly named mineral found as an inclusion in a diamond. The mineral had been made in high pressure, high temperature laboratories but the authors are among the first to find it in nature and the first to, officially, name it. 

The composition is the same as wollastonite (see HERE) CaSiO₃, and has been called davemaoite. It is thought to be the third most abundant mineral in the lower mantle and is capable of holding various isotopes of uranium, thorium and potassium. And it is these isotopes which generate a lot of the heat in this part of the mantle.

The inclusions in the diamond must be at a very high pressure as the mineral cannot exist at surface pressures. You can make a mineral but you cannot name it as a mineral if it is not found as naturally occurring. Being tiny and in a diamond counts as naturally occurring!


This diamond holds tiny black specks of davemaoite, a mineral formed at high temperature and pressure in the deep Earth. Credit: Aaron Celestian, Natural History Museum of Los Angeles County

Wednesday 10 November 2021

Explosive Lake Kivu - an audio long-read

Explosive Lake Kivu - an audio long-read 

Lake Kivu has 300 cubic kilometres of dissolved carbon monoxide 60 cubic kilometres of methane! 

You can listen very pleasantly to a long-read from Nature HERE and find out about the science, the business and the politics - nothing is ever easy!

Saturday 6 November 2021

Planetesimals or Pebbles

Planetesimals or Pebbles 

How do planets form? For decades, when asked, people like me would mutter something about planetesimals and quickly move on. THIS ARTICLE suggests that the word I should mutter is pebbles. And tell people to read the article!

Apparently there was some difficulty about planetesimals - it would take too long for them to form. A planet like Jupiter would take tens of millions of years to form a core, by which time the protoplanetary disc from which they would need to accumulate gas would no longer exist. Instead of planetesimals, measured in 100's of kilometres, pebbles, measured in millimetres and centimetres, were the answer. And todays telescopes could see them.


  
ALMA observations of protoplanetary disk around HL Tauri in 2014 revealed hidden structures, including the presence of pebbles in the disk.

ALMA (ESO/NAOJ/NRAO)

The pebble theory rapidly gained acceptance for the giant planets but it has difficulties for smaller planets like the Earth. The article discusses this and comes to no definite conclusion. I suspect that debate will continue for years and, eventually a consensus will be reached. 

In the meantime the word is pebbles - probably!

Thursday 4 November 2021

Down to Earth Extra - November 2021

 Down to Earth Extra - November 2021 


The latest edition of Down to Earth Extra is HERE.

And you can read it below.  


La Palma Videos

La Palma Videos 

A correspondent has told me that these three videos are well worth viewing, especially the first and the third. I quite agree!

Eruption Update




The Noisy Volcano



The Lava Delta


Saturday 23 October 2021

Were Dinosaurs Good Neighbours?

Were Dinosaurs Good Neighbours? 

A correspondent has sent me THIS LINK - many thanks. In it Mike Benton discusses whether dinosaurs were social animals. The basis of his discussion is THIS PAPER. the researchers have found and described a site in Patagonia where they found nests with eggs and the skeletons of Mussaurus patagonicus. The skeletons ranged from babies to adults. The age is given as 193 million years.

The nests were spaced at a distance consistent with the animals size - close but not too close. It is suggested that they returned to the site regularly. There is evidence that it is a life assemblage - at least for the eggs - perhaps a dust storm buried the eggs. The skeletons are mostly complete and therefore are at the place they died.

So did these dinosaurs live in family groups? Mike Benton is beginning to think so - dinosaurs were warm-blooded, feathered, fast-moving and had sophisticated behaviour.


The research team studied fossils at an early Jurassic site in Patagonia, Argentina. Alejandro OTero

Thursday 14 October 2021

Two Contrasting Landslides

Two Contrasting Landslides 

I came across these two articles on The Landslide Blog

THE FIRST is probably the slowest landslide measured - 2mm per year. It is big - a block of limestone 900m by 400m sliding over a layer of clays and marls. It is in Tunisia and it looks spectacular. Obviously a still photograph rather than a video.



THE SECOND is rather faster. It occurred in the Dolomites on the 9th October at the Punta dei Ross, Croda Marcora.


It becomes rather hectic at the 38 second mark. The measurements become m per sec rather than mm per year.

Both landslides are fascinating.

Saturday 9 October 2021

The Moon's Youngest Rocks

 The Moon's Youngest Rocks

A Chinese Moon lander has come back with the youngest rocks yet found on the Moon. 1.97 billion year old basalt lavas, to be precise. This age is a lot younger than anyone had predicted. Where did the heat come from to produce liquid magma? Tidal heating is today's hot prediction, but nobody really knows. 

The rocks were retrieved by the Chang'e-5 mission which landed on the moon in December 2020. Read all about it HERE

The site for the lander was selected by counting craters! The less the crater density, the younger the surface. The age found vindicates this method of dating the relative ages of areas of the Moons surface.

Explaining the age of the lava should keep people busy for ages!


The landing site. CNSA Lunar Exploration and Space Engineering Center, Author

Thursday 7 October 2021

Earthshine Decreasing

Earthshine Decreasing 

The reason we are able to see a new Moon is because it is lit by reflected light from the Earth - earthshine. The amount of earthshine is controlled by the Earth's albedo - the higher the albedo the more earthshine. In the last ice age the albedo was high as ice is a good reflector. Cloud cover acts in the same way. 

The source of the light is, of course, the Sun. And with light comes heat. Generally 30% of the solar energy hitting the Earth is reflected - the albedo at work.

How do you measure the albedo? THIS ARTICLE based on THIS PAPER tells you how and it is based on measuring earthshine. (Jokes about moonshine will not be tolerated!) The investigators have been measuring earthshine on the moon since 1998 and have found that it has decreased by an amount indicating a 0.5% decrease in the albedo. A decrease in the energy reflected out indicates an increase in the energy received by the Earth.

In the ice ages high albedo encouraged cooling; now the decreasing albedo is increasing global warming.

Surprisingly the change in the albedo is attributed to a shortage of low altitude clouds over the eastern Pacific.

Wednesday 22 September 2021

Down to Earth Extra - October 2021

  Down to Earth Extra - October 2021 
 
The latest edition of Down to Earth Extra is HERE.

And you can read it below.


 

Tuesday 21 September 2021

Apocalypse Then

Apocalypse Then 

I came across THIS ARTICLE today and thought it very interesting if not particularly geological. It is a popularisation of THIS PAPER in Nature.

It concerns the total destruction of Tall el-Hammam, a Middle Bronze Age city north east of the Dead Sea, in Jordan. This occurred about 3,600 years ago and it is speculated that it may have inspired the Old Testament story of the annihilation of Sodom. There is a Lot of evidence. (Sorry!)

The site has been excavated for 15 years and is continuing. Objects found which are of interest include, pottery sherds with glassy surfaces, melted mudbrick fragments, melted building plaster. One begins to think of an extremely high temperature event.

Also the buildings did not just fall down - they were levelled. Walls were sheared off. Most of the mud bricks were pulverised and blown off the site to the north east.

Could this be signs of warfare - No. There is a complete lack of arrowheads, sling stones and spear points at the destruction layer.

The researchers did not find nanodiamonds (often found at sites of cosmic impact) but they did find diamonoid particles - the smallest unit found in the diamond crystal lattice. Shocked quartz was also found.

There is much more evidence described in the articles and they all lead to the conclusion that there was a cosmic airburst a bit bigger than the Tunguska event in Siberia in 1908.

Both articles are well worth reading. And both are free!

The comments on the first article are enlightening and entertaining. The suggestion that the Sumerians had atomic bombs but not wheels is dismissed.


Catastrophic leveling of the palace at TeH. (a) Artist’s evidence-based reconstruction of the 4-to-5-story palace that was ~ 52 m long and 27 m wide before its destruction. (b) Artist’s evidence-based reconstruction of palace site on upper tall, along with modern excavation. “MB II” marks the top of 1650-BCE Middle Bronze rubble. Note that the field around the excavation is essentially flat, unlike the view in panel ‘a’. Originally, parts of the 4-story palace were ~ 12 + m tall, but afterward, only a few courses of mudbricks remain on stone foundations, labeled as “wall remnants”. Part of the foundation of the massive wall around the palace is at the bottom. Debris from between sheared walls has been removed by excavation. A comparison of panel ‘a’ to panel ‘b’ shows that millions of mudbricks from the upper parts of the palace and other buildings are missing.


Saturday 18 September 2021

Meet the Magma Tree

Meet the Magma Tree 

Two correspondents have brought THIS ARTICLE to my attention - many thanks and keep them coming! The article is based on AN ARTICLE (£) in Nature Geoscience. (The pound sign indicates that you need to pay to read it.)

The article describes research which has been going on for decades. Using seismometers to determine the inner structure of the earth is now developing to describe the plumes which bring volcanism to the unexpected parts of the globe. And now researchers think they have found "a titanic mantle plume "tree"" which rises from core mantle boundary.

One of the branches of the tree hits the surface at the Indian Ocean island of La Réunion. It has an extremely active volcano but is more than 1,000km from the nearest plate boundary. It is the current end of a track which leads to the Deccan Traps of India which produced 10⁶km³ of basalt around 65 million years ago.

Much effort has been expended in mapping the Réunion plume and the other plumes of the magma tree and the articles describe how they look as they do. And also does some predictions into the future - Africa seems to have a fiery future!

There is far too much to describe here - read the article!


The caldera of the Piton de la Fournaise on Réunion.
Henner Damke/Shutterstock

Thursday 9 September 2021

Underwater Glacial Geomorphology

Underwater Glacial Geomorphology 

A correspondent spotted THIS on the BBC website and passed it on to me.

It concerns sub-glacial landforms which were made under ancient ice sheets. These were where the North Sea is now and have only recently been discovered using seismic survey techniques. Deep seismic techniques are used to find possible oil bearing structures, these shallow ones were originally developed to find suitable foundations for oil industry infrastructure,

The structures may give us a picture of what is happening beneath Greenland's ice cap as it melts under today's conditions of global warming.



How the Moon Made Life on Earth Possible

How the Moon Made Life on Earth Possible

A  correspondent brought two links to my notice. THE FIRST is the scientific paper on which THE SECOND (a YouTube Video) is based. If you are anything like me you will find the video much more approachable.

The thesis is multi staged. 
  • The moon slows down the rotation of the Earth.
  • Oxygen producing cyanobacteria rise to the sea surface during daylight.
  • Anaerobic bacteria rise to the sea surface at night.
  • Cyanobacteria rise slowly.
  • When day length is short cyanobacteria are not in daylight for long.
  • Longer days mean more oxygen produced.
  • Oxygen in the atmosphere allows multicellular life to develop.
You can read all about it in the Nature paper, or you can watch the video. Also in the video you have the chance to buy a T shirt!!!

You can read about the sinkholes which feature in the previous links HERE.




A term used in both paper and video is "diel". It is one I had not come across before. It is usually phrased as diel vertical migration, and Wikipedia defines it as:- 

Diel vertical migration (DVM), also known as diurnal vertical migration, is a pattern of movement used by some organisms, such as copepods, living in the ocean and in lakes. The migration occurs when organisms move up to the uppermost layer of the sea at night and return to the bottom of the daylight zone of the oceans or to the dense, bottom layer of lakes during the day. The word diel comes from the Latin dies day, and means a 24-hour period. In terms of biomass, it is the greatest migration in the world. It is not restricted to any one taxon as examples are known from crustaceans (copepods), molluscs (squid), and ray-finned fishes (trout). Various stimuli are responsible for this phenomenon, the most prominent being response to changes in light intensity, though evidence suggests that biological clocks are an underlying stimulus as well. The phenomenon may arise for a number of reasons, though it is most typically to access food and avoid predators. While this mass migration is generally nocturnal, with the animals ascending from the depths at nightfall and descending at sunrise, the timing can be altered in response to the different cues and stimuli that trigger it. Some unusual events impact vertical migration: DVM is absent during the midnight sun in Arctic regions and vertical migration can occur suddenly during a solar eclipse.

Saturday 4 September 2021

Dave Green's Programme for 2021 - 22

Dave Green's Programme for 2021 - 22 

Dave Green has produced a programme for the next year which is bursting with geological goodness!. I have put down my name for the trip to the Eastern Pyrenees next February already!

You can download the programme HERE.

Or read it below. 


Friday 3 September 2021

Down to Earth Extra - September 2021

  Down to Earth Extra - September 2021 
 
The latest edition of Down to Earth Extra is HERE.

And you can read it below.


Sunday 29 August 2021

A Podcast About the Ediacaran

A Podcast About the Ediacaran 

I came across this podcast and thought it might be of interest. You can listen to it HERE.

It tells about the finding of the fossils and the geologist, Reg Spriggs, who found them. Also the campaign to get the area declared a Conservation Park.



Saturday 28 August 2021

The Ancestor of All Scaled Reptiles

The Ancestor of All Scaled Reptiles 

THIS ARTICLE tells us of a very well preserved, but tiny (32mm), fossil found in north west Argentina in 231 million year old (Late Triassic) sediments. It is described as the most primitive scaled reptile yet found.

It is a Lepidosaur - a group which contains lizards and snakes - the most diverse group of terrestrial vertebrates presently alive. But very little is known of their early origins. I has been named Taytalura alcoberi.

The enormous reptiles of the period are well known. In contrast, the little ones are almost unknown. It is hoped that this specimen will lead to the areas of ignorance being diminished.

If you have access you can read the original paper HERE.


Life restoration of the Taytalura skull. (Jorge Blanco, Gabriela Sobral and Ricardo Martínez).

Police Raid Finds Flying Reptile Fossil

Police Raid Finds Flying Reptile Fossil 

Yet another correspondent directed me to THIS ARTICLE. It tells us that a police raid in São Paulo found six limestone slabs with a very well preserved fossil of Tupandactylus navigans, a member of the Tapejarid subgroup of the pterosaurs


You can find a much larger version of this HERE

Tupandactylus navigans fossils are commonly found in Brazil but usually only the head is preserved. This is the most complete tapejarid skeleton ever found in Brazil.

I wish I knew more of how the police raid happened and did the "owners" know what they had.

The scientific description of the specimen can be found HERE.

All You Need to Know About Dog Vomit Slime Mould

All You Need to Know About Dog Vomit Slime Mould 

A correspondent brought THIS ARTICLE to my notice. As she said it is not very geological - slime moulds (actually myxomycetes) have a limited place in the fossil record - but it is a fascinating read. 

If you want to know about a single cell that can grow as large as a bath mat, has no brain, no sense of sight or smell, but can solve mazes, learn patterns, keep time, and pass down the wisdom of generations, read the article!

The slime mould is used by the author to talk about the classification of nature and the creation of hierarchies. All in all a very good read.


Badhamia utricularis

Four-Legged Egyptian Whale

Four-Legged Egyptian Whale 

Two correspondents directed me to this fossil find made in the Fayum Depression in Egypt. The beastie lived 43 million years ago and marks the transition from, as Darwin said, "something like a bear" to modern whales.

You can read all about it HERE and HERE.


An imagined reconstruction of Phiomicetus anubis by palentologist Dr Robert Boessenecker

(Robert Boessenecker)

Wednesday 25 August 2021

The Five Most Impressive Geological Structures in the Solar System

The Five Most Impressive Geological Structures in the Solar System 

Or - Field trips I would like to go on.

I came across THIS ARTICLE and, although it has little to do with the West Country, could not resist putting it into the blog.

My favourites are the fold mountains of Venus and the drowned coastline of Titan. 


Fold mountains in Ovda Regio, Venus. The insert is a similar view of part of the Applachians in central Pennsylvania. NASA/JPL


Left: Part of Titan’s Ligeia Mare, showing a coastline with valleys drowned by a sea of liquid methane. Right: The Musandam peninsula, Arabia, where coastal valleys are similarly drowned, but by a saltwater sea. NASA/JPL-Caltech/ASI/Cornell and Expedition 63, International Space Station (ISS)

Thursday 19 August 2021

Mars in 4K Resolution

Mars in 4K Resolution 

Various sources have brought this video to my attention. The pictures are amazing  (Very Good). So is the commentary (Words good, Voice awful).

You can see it HERE, or watch it below.



Bath Walking Trails

Bath Walking Trails 

A correspondent from Bath Royal Literary and Scientific Institution has sent me some information on four walks around Bath, some of which will be of interest to geologists. They are all of interest to everyone!

She Writes:-
----------------------------------------------------
I wonder if you would be interesting in circulating the information below about the new BRLSI Bath Discovery Trails, accessed with a free App for Android and Apple Smartphones, produced in collaboration with BathSpa University? I think some of these will interest your readers.



The four walking trails are: The First Meteorite, The Railway Leviathan, On the Origin of Species and The War Crosses.



All you need is your phone and a decent pair of shoes; the trails take about 1.5 - 2 hours to walk, but you can easily skip sections or take a break along the way if you feel the need! Bath Royal Literary & Scientific Institution is open 10-4, Monday to Saturday.



The First Meteorite

This centres on an object from outer space that is small enough to fit in your hand and is 4.2 billion years old. This trail explores ‘deep time’ and the very origins of our solar system through a story that connects 18th-century astronomers with druid temples and a Siberian forest. Once you have completed your journey to BRLSI you will be able to see this unique fragment from the earliest years of the universe.

Activation Code: bathdiscovery3



The Railway Leviathan

Rediscover a lost world, here in Bath. This trail brings to life extinct species from a time before human beings and explains how the industrialisation of Bath’s landscape in the nineteenth century unearthed long lost creatures that once roamed the land and swam in the seas where Bath now stands—and how BRLSI was crucial in preserving that prehistoric past. At the end of this trail you will be able to view the skull of a Jurassic steneosaurus, just one of BRLSI’s many fossils.

Activation Code: bathdiscovery4



The Origin of Species

Learn about one of the world’s most important scientific books through the lens of a very local friendship. Charles Darwin spent his life gathering data based on his observations of animals and plants, which would lead to the development of the theory of evolution. This trail explores the lifelong friendship between Darwin and Leonard Jenyns, who lived here in Bath, through a correspondence that reveals a shared love for natural history and intellectual curiosity about the natural world. Jenyns donated his library to BRLSI and, once you have completed the trail, you will be able to see his own copy of Darwin’s On the Origin of Species, alongside a letter he wrote to Darwin.

Activation Code: bathdiscovery2



The War Crosses

Take a closer look at the human cost of conflict through the city’s war memorials and the soldiers who experienced this first industrialised war. In this trail you will discover the places where returning soldiers were treated for their injuries, the houses where army generals lived, and the memorials to the fallen. Once you complete the trail you will be able to view relics of the Crimean War, part of BRLSI’s extensive collections related to human conflict across the centuries.

Activation Code: bathdiscovery1



You can download the app for free via your usual provider or just click on the links:






---------------------------------

Saturday 14 August 2021

Join the Avon RIGS Group

Join the Avon RIGS Group 

As the threat of Covid seems to be in retreat, the prospect of field work advances.

And an opportunity for field work is with the local RIGS group. RIGS (regionally Important Geological Sites) is administered by BRERC (Bristol Regional Environmental Recording Centre) which is based at Blaise Castle House Museum. 

A look at BRERC's web site (see HERE) shows it is mainly concerned with wildlife but it is trying to enliven its geological footprint. There are many RIGS in this area and many have not been looked at in decades. Joining the RIGS group will help get the data base up to date. 

The tasks can range from the easy - does the site still exist?, is it overgrown, has it been built on, is it accessible - to the more exacting - what are its exact boundaries, does it show what it is said to show.

The first step to help with this endeavour is to join the Group. To do so send an email to Tim Corner at tim.corner@brerc.org.uk asking to join.

Friday 13 August 2021

Does Global Warming Lead to Mass Extinction?

Does Global Warming Lead to Mass Extinction? 

We know when mass extinctions have happened; we know the sea surface temperature for many millions of years. Is there a connection?

THIS ARTICLE, based on THIS PAPER, looks at this. And the news is not good!

Data for the two sets is usually not presented in similar ways. Extinction data usually comes as number of disappearances per geological stage; sea surface temperature is more nearly continuous.

To make correlations the authors put the data into 10 million year time bins and this is what you see below.


Changes since the end of the Ordovician: red = extinction rate in time bins; green = the greatest magnitude of change in temperature in each bin; blue- the greatest rate of temperature change in each bin. Grey bars show mass extinctions (Credit: Song et al., Fig 1)

The data shows that there is a good correlation between the two data sets. When the sea surface temperature rises quickly, mass extinctions happen. 

And the sea surface temperature is rising very fast indeeed.


Monday 9 August 2021

Jurassic Ark – Spectacular Fossils from an Ancient Somerset Sea

 Jurassic Ark – Spectacular Fossils from an Ancient Somerset Sea



A Summer Exhibition, with free entry, at the Bath Royal Literary & Scientific Institution (BRLSI), 16 Queen Square, Bath BA1 2HN, until 2nd October, 10am–4pm Monday–Saturday.



The Bath Royal Literary and Scientific Institution is celebrating their unique collection of fossils from the Lower Jurassic of Strawberry Bank. Beneath the Somerset town of Ilminster, lies a beautifully-preserved Jurassic ecosystem, from which Victorian geologist Charles Moore collected hundreds of fossils. The fossils show exceptional preservation, revealing soft tissues such as muscles, guts, and traces of skin. Importantly, they retain the animals’ original three-dimensional shape. Uncompressed, three-dimensional fossils that preserve soft tissues are very rare, and the concentration of a diverse fauna at this site makes it one of the best-preserved Lower Jurassic marine ecosystems in the world.



Specially commissioned illustrations by John Sibbick, one of the world's foremost palaeontological illustrators, recreate the landscape in which these extinct marine reptiles, fish, crustaceans, squid-like cephalopods, and insects flourished.



Although Moore’s original quarry was infilled in 1860, a new excavation in 2019, headed by the BRLSI, opened two trenches to study the strata of what is now called the ‘Strawberry Bank Lagerstätte’.



These extraordinary fossils have been studied in depth as part of a four-year project of intensive research through the JESBI project, an exciting collaboration between the BRLSI Collections team and Bristol University, funded by the Esmée Fairbairn Foundation. Professor Mike Benton of the University of Bristol is excited to see the findings of the project presented to a wider audience. He said “The fossils may be old, and they were collected 170 years ago, but they are providing remarkable new scientific information.”

------------------------------------------------------

An introduction to the exhibition can be seen HERE.

A video of the making of the exhibition can be seen HERE.

A short film about the research done on a Strawberry Bank ichthyosaur skull from the exhibition, in collaboration with the University of Bristol can be found HERE.

A series of three talks connected to the Strawberry Bank fossils which can be viewed on the BRLSI YouTube channel.

The suggested order of viewing is:-

Saturday 7 August 2021

Down to Earth Extra - August 2021

 Down to Earth Extra - August 2021 

 
The latest edition of Down to Earth Extra is HERE.

And you can read it below.

Sea Level Changes Affect Eruptions

Sea Level Changes Affect Eruptions 

Many thanks to a correspondent who brought THIS ARTICLE to my attention. It is based on THIS ARTICLE in Nature.

It is based on a study of Santorini which looked at sea level and eruptions. The data covers the last 360 thousand years. In that period there were 211 eruptions, 208 occurred when sea level was low.

The theory is that when sea level is high (as it is now) the pressure on the magma chamber (4km down) keeps the roof intact. When sea level drops by 40m the pressure on the magma chamber roof lessens, cracks develop, magma, in the form of dykes, moves upwards. At a sea level drop of 70m the dykes reach the surface. 

The study suggests that it takes 13,000 years for the cracks to reach the surface. The eruption which may have been the demise of the Minoan Civilization occurred in 1,600BCE, the sea level was last below -40m 11,000 years ago, so we are in a quiet period as sea level continues to rise.



Friday 6 August 2021

How Old Are Sponges?- Continued

How Old Are Sponges?- Continued 

Last weeks POST on sponges was the subject of a NATURE PODCAST. You can listen to it on the link.


Sunday 1 August 2021

Seatown Landslide

Seatown Landslide 

I came across this on Facebook and thought you might find it interesting. The original post on Facebook is HERE.



Saturday 31 July 2021

How Old are Sponges?

How Old are Sponges? 

A correspondent sent me the link for THIS ARTICLE - many thanks. It is based on THIS ARTICLE in Nature. 

The researcher, working on 890 million year old reef rocks, found structure in some of her thin sections which looked rather like those found in more modern rocks. She did this 10 years ago. In the intervening period there have been many publications which have identified similar structures as being sponges.

But her rocks were more than 400 million years older than the oldest confirmed sponge. And the oxygen content of sea and atmosphere was rather different. But she argues that the cyanobacteria, that made the reefs she was working on, were close enough to her sponges to provide enough oxygen.

So, perhaps sponges are the oldest animals and were around for a lot longer than we thought.


ABOVE: A low-magnification view of the connected network of tunnels that form a putative sponge protein skeleton fossil found in an 890-million-year-old rock. The field of view is about 9 millimeters.
EC TURNER

 

The Earth's Inner Core

The Earth's Inner Core 

I came across THIS ARTICLE and now know more about the inner core than I did before - and some of it is very surprising!

The inner core is solid but is very hot and under great pressure. Previously it was even hotter and was liquid. When did the temperature drop low enough to allow solid iron to appear? Between 500 and 1,500 million years ago. People discovered its existence in 1936.

Its radius increases by 1mm per year. This implies 8,000 tonnes of iron solidify every second! Eventually all the core will solidify and the Earth will not have a magnetic field.

The inner core is lop-sided. The eastern part, under Indonesia, is growing faster than the western part, under Brazil. But, thankfully, gravitational forces sort things out and the core remains spherical.

The article tells us how all this is surmised - none of this can be found first hand! Read the page - there is lots of good stuff therein.


Seismic waves have suggested Earth’s solid iron core is asymmetrical. Sanne Cottaar, Author provided

Saturday 24 July 2021

A "Jurassic Pompeii" - Somewhere in the Cotswolds

A "Jurassic Pompeii" - Somewhere in the Cotswolds 

Many of you must have seen THIS WEB PAGE from the BBC. A correspondent brought it to my attention - Thank You!

At first glance the article looks like a very superficial piece of work, but it isn't. There is a lot of information about the geology, the palaeontology, the sedimentology and the excitement of scientific discovery. Read all the page - it goes on for a long way - look at the photos, play the videos. It is a good example of making geology interesting.

At the moment the location is secret. No doubt, some of you can work out where it is. I look forward to seeing the specimens in the Natural History Museum.


Frozen in time: Fossilised seafloor animals from the Jurassic, all piled on top of each other

Seismology of Mars

Seismology of Mars 

A few years a go WEGA had a lecture from a Bristol University lecturer on this subject. He was somewhat limited as the only seismometer on Mars was ON a lander which had a very effective suspension. He thought that you would need an earthquake marsquake above 8 on the Richter scale to be recorded! So a lot of his talk was about the next seismometer on Mars. 

And that seismometer is the subject of THIS ARTICLE by two researchers at Bristol. 

The seismometer has detected hundreds of quakes and the conclusion is that Mars has a much larger core than previously thought. Because it is larger it must have a larger proportion of lighter elements than Earths core. And such a composition would not have an inner solid core - and hence no magnetic field.

The crust of Mars has been estimated from the quakes as 24 to 72km thick and the lithosphere 400 to 600km.

Shear waves travel from a marsquake and reflect off the iron-nickel core. Chris Bickel/Science