An Unsurprising Discovery

A correspondent sent me THIS LINK. It is based on this ACADEMIC PAPER in Nature. The Nature paper concentrates on the history of the breakup of the ice shelves which fringed the British-Irish Ice Sheet (BIIS). The BBC article concentrates on the scratches the icebergs breaking off from the ice shelves left on the sea floor. 

It has always seemed to me that such scratches would inevitably be found some time; - there was an ice sheet; icebergs would be spawned; icebergs would leave sea bed scratches. So it is nice that there presence has been proved.

The paper in Nature uses the scratches to detail how the BIIS retreated and uses the data to model how the Antarctic Ice Sheet might break up.

Icebergs calved in the Witch Ground Basin would drift eastwards towards the Norwegian Channel before being routed northwards towards the continental shelf edge. The isostatically-corrected bathymetry of the central North Sea at 20 ka is from Bradley et al. 60, with bathymetric depth contours displayed every 25 m. Colored stippled lines represent the modeled ice margins of the last British-Irish (BIIS) and Fennoscandian (FIS) ice sheets at timeslices between 20 ka and 18 ka from Clark et al. 40. NCIS—Norwegian Channel Ice Stream.

 Petrification: Fossils & the Revelation of Deep Time

News has come to me of this free exhibition at the Bath Royal Literary & Scientific Institution and it sounds very interesting. It runs until Saturday 11th October.

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What makes fossils so special? Fossils provide the evidence that there was life on earth before humans and this year Bath Royal Literary and Scientific Institution is displaying a selection of the best from the depths of our amazing collections. Petrification is BRLSI’s latest exhibition and in it you will discover fossils from across 505 million years of the history of life. The BRLSI’s earliest fossil is a trilobite from the Cambrian geological period!

Our exhibition begins by encouraging visitors to follow a Deep Timeline, starting out at a meteorite which represents the formation of both the Solar System and planet Earth 4.567 billion years ago!

Crossing the gallery, the timeline leads visitors through the Precambrian era, when only single-celled life existed, all the way through to the Cambrian Explosion of life. The final ninth of the timeline, which is depicted in a scale running up the wall of the gallery, is where all the palaeontologic action happens.

This is where visitors get to experience trilobites and corals, dinosaurs, marine reptiles, mammoths and cave bears! Colour-coded exhibits in the room correspond to the timeline so that visitors always know where in Deep Time they are.

And that’s really just the start! Learn more about some of the amazing things you can hope to find in Petrification, and our accompanying activities for families and children here.

Come to BRLSI and discover the beautiful complexity of prehistoric life and Bath’s influential role in the birth of palaeontology.

Please note our opening hours are Monday to Saturday, 10am to 4pm (closed on Sundays).

We are open Good Friday (18 April) and Easter Monday (21 April).

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 Filling the Mediterranean - a Megaflood of Articles

It has probably not escaped your notice that there has been a plethora of articles in the last few days about the flooding of the Mediterranean when the barrier at Gibraltar was breached. It has been on YouTube HERE, HERE, HERE, HERE, HERE and many more; on various web sites such as HERE and HERE. It has also featured on my FAVOURITE PODCAST. I could go on but you get the picture.

All these eruptions of interest, except the podcast, are due to THIS PAPER which discusses, in some depth, the geomorphological results of the refilling of the Mediterranean, especially the part east of Sicily.

I first became aware of the drying of the Mediterranean when I read about the difficulty the builders of the Aswan Dam had in finding hard rock for the dams foundations. They discovered that there was a deep canyon along the Nile caused by the river eroding downwards to a base level far below the present Mediterranean. The canyon had been filled in with sediments deposited when the base level rose back to its present position. 

The interest in the refilling shows the publics interest in exciting stories and the stories don't get any more exciting than the Gibraltar waterfall!

 

 The Case of the Missing Niobium

A correspondent sent me THIS LINK. As he said, it is very interesting but I admit I found it rather difficult to understand. So, being a bit of a tech wizard, I decided to get some help from my pal Gemini, and asked it to summarise the article in less than 200 words. I reckon it did a good job and I understand it much more. Read and see if you agree.

I wish Gemini and its like had been around when I was at University!

Below is Gemini's summary.

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A new study challenges the long-held assumption that Earth's early crust was significantly different from today's continental crust. Researchers used mathematical models to simulate the formation of Earth's first protocrust during the Hadean eon (4 to 4.5 billion years ago). Their findings suggest that this early crust surprisingly exhibited a similar chemical fingerprint to modern continental crust, specifically a lack of the element niobium.

This niobium depletion was previously thought to be a hallmark of subduction zones, implying the existence of tectonic plates early on. However, the model indicates that niobium would have been drawn to Earth's core during its formation, explaining its absence in the early crust without the need for plate tectonics. This suggests that continental crust formation may have been an original part of Earth's layering process. The study offers a new perspective on Earth's early geological evolution and potentially the formation of continents on other planets.

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 Somerset Geology Group - 2025 Update

The Somerset Geology Group has published its update for spring 2025 and it contains much of interest. You can download it HERE and you can read it in this blog below.

They have a new website which you can see at https://somersetgeology.org.uk.

And they have update Hugh Prudden's Bibliography of Somerset Geology. You can download the updated version HERE, and compare it to the old version which you can get HERE.

As a result of the update I have changed a couple of web pages - https://westcountrygeology.com/somerset-papers/ and 

https://bristolgeology.com/somerset-papers/. Because incorporating pdf files into my web pages is not easy I have converted them to Word files but this entails a small loss of formatting.

 CARDIFF UNIVERSITY GEOLOGY FIELD COURSE FOR ADULTS

Nick Chidlaw has contacted me about a course he is running this summer in association with Cardiff University Lifelong Learning. The details are given below.

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I am offering to run a field course for 4 consecutive days in June this year.  This is organised by Lifelong Learning at Cardiff University and examines the geology at key locations in and between the Malvern Hills and the Cotswolds.  

Enrolees do not need to be students studying at Cardiff University - it is intended and available for the adult public.

Please see attachment for details, and for contacting Lifelong Learning. The course fee is £196.00, concessionary fee £157.00 .

The Attachment is HERE.

No prior knowledge of geology or the study area is assumed.

The course carries assessment, which is completed after the course is run and returned to the tutor within 14 days.  It is designed to be easily completed (ticking boxes, filling in words only) and in practise course attendees find the process enjoyable and useful for consolidating what they've learned. There is only a 'pass' or 'fail' grading: a pass is 40%.

Most course attendees score very highly - usually above 80%, with some getting scores in the high 90's.

Any queries you have about the course content, do contact me; enrolling and course payment is done through Lifelong Learning at Cardiff (contact details given in attached doc).

I hope you find this proposal of interest, that you're available and that you decide to enrol.

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You can read the attachment below. Nick is referring to the central item.

 Night and Day - Driver of Diversity!

I have come across a couple of articles which are promoting the idea that daily changes in the oxygen content of shallow shelf seas in the Cambrian were a major driver of the diversification of animal life in the "Cambrian Explosion". You can read about it HERE and HERE. The inspiration for both articles is THIS PAPER in Nature.

The main point of the paper is that in shallow shelf seas the amount of oxygen in the water would change, depending on the amount of sunlight. During the day, photosynthesis would increase the amount of oxygen in the water. But at night the decay of organic matter on the sea bed would reduce the amount of dissolved oxygen. This rejoices in the term ""benthic diel oxygen variability". Diel was a new word for me and means "involving a 24 hour period". Whether days were 24 hours long in the Cambrian is a rabbit hole we will not go down!

An animal in such a shelf sea would have to cope with wildly varying oxygen content in the water in which it lived. Those that survived would do so by becoming more diverse - or so the authors believe.

At this boundary, the temporal extent of potentially global glaciations of the Cryogenian (blue vertical fields) is depicted as well as this study’s region of interest (ROI). 

A The sandy shelf area in Laurentia and its increase in extent over the Neoproterozoic-Palaeozoic, from ref. 14 (black line, grey field represent bootstrap resampled error at ±1 std. dev.). 

B One modelled global average surface air temperature representation (at low latitude) modified from ref. 34, see also supplementary information and Supplementary Fig. 1 for comparison with clumped isotope data from ref. 27. Grey field represent ±1 std. dev and +25 °C marking a transition from cold (blue) and warm (red) climate states. A gradual shift from an icehouse to a greenhouse climate (blue-red colour). 

C The divergence of animal clades (one of several possible time-calibrated trees, based on ref. 96, with approximate divergence between lineages based on ref. 97 and ref. 71). Boxes represent early branching clades and Bilateria that today perform cellular oxygen sensing mechanisms with the Hypoxia-Inducible Factor (HIF) system (filled orange) or not (grey), based on refs. 43,53. The positions of Ctenophora and Placozoa are based on ref. 96.

 Down to Earth Extra April 2025

The April 2025 edition of Down to Earth Extra has been published. You can download it HERE or you can read it below.

 Strange Fossil Preservation

If you are fossil hunting, one place you would not bother with is a pyroclastic flow. But THIS ARTICLE describes the finding of a wonderfully preserved griffon vulture in volcanic rocks not far from Rome. This was in 1889. A distinguished geologist (not the finder) identified the bird and noted that he preservation was unusual. And then it was forgotten about.

Then, more recently, the remaining specimens were re-examined and found to be extremely well preserved. The head and neck were CT scanned and the creatures eyelids, tongue and skin texture were seen in great detail.

Studies were extended to the birds feathers and they also were exquisitely preserved down to the finest structures. And the feathers had been replaced by zeolite!

So now palaeontologists have a new rock type to search!

 

 How to Analyse Past Atmospheres

I came across THIS ARTICLE and found it very interesting. It describes methods used to extract and analyse gases trapped in rocks and minerals. The gases are in  various salts, quartz and crystallized magmas.

The technique used sounds simple - crush the rock and collect the gas. But it has to be done in a vacuum-sealed press and send the released gas to a mass spectrometer for analysis. The gas does not all come out at once but in pulses as different parts of the sample fail. Repeat and repeat until you have enough gas. The crushers are very small - 10 grams of rock is considered "an insane quantity"!

Crush Archaean rocks and with care you can get a sample of Archaean air. Its age can be proved by radiometric dating of the included noble gas isotopes. There have been some surprises - higher oxygen levels appearing earlier than expected.

But read the article to get an introduction to this fascinating subject.

 Is There Helium in the Core?

A correspondent sent me THIS LINK which seems to link three opposites. Helium is a very light noble gas which does not mix with anything, iron is a metal and the earths core is hot, pressurised and a long way away. But there are hints that all is not as one assumes!

The rare (at the Earths surface) form of helium is He-3 (2 protons, one neutron) is found during volcanic eruptions. Where did it come from? Is it left over from the Big Bang? 

In normal circumstances you can find a few parts per million of helium in iron. The experimenters decided to look at conditions similar to those of the Earth' core. For this they used a laser heated diamond anvil cell. And found that they could get 3.3% helium into iron.

If this is what actually happens in the core it has implications for what happened as the Earth formed. And it may mean that the helium from volcanic action came from the core and not from, as yet unfound, reservoirs. What I find mind boggling is the scaling up from tiny experimental quantities to the Earth's core!

 Was Human Life Dependent on Five "Hard Steps"?

I wish I knew! THIS PAPER suggests not, but first of all - What Are The Five Steps? They are the things which had to happen for human life to exist. And it is soon evident that much academic blood has been spilled over the compilation of the list. But here is one version of it.

1. Life (abiogenesis)
   
   
2. Oxygenic photosynthesis
   
   
3. Eukaryotic cells - fusion of a Bacteria with an Archaea
   
   
4. Animal multicellularity
   
   
5. Homo sapiens

The order of the steps is fixed. Steps 1, 3 and 4 are evolutionary steps, 2 and 5 are not. Various other steps have been proposed but five seems a good number. A definition of a hard step is:- Improbable, and essential for the evolution of humanity.

These hard steps are fairly evenly distributed over the life of the Earth.

The authors of this article suggest that these singularities are the result of the global-enviromental processes. They may have happened once but the happening was inevitable.

This is a very interesting article and you need to read it to get an appreciation of the knowledge used in it. But the conclusion seems to imply that human like beings should be fairly common in the universe. So far we have discovered only us. Are the authors wrong or is there something preventing intragalactic communication?

 Down to Earth Extra March 2025

The March 2025 edition of Down to Earth Extra has been published. You can download it HERE or you can read it below.

 Does the Inner Core Change Shape?

And if it does, how do we tell and does it matter? The Inner Core is solid, the Outer core is liquid. Both are thought to be largely iron. The Core is responsible for the Earth's magnetic field, without which life on Earth would not be possible. And it is studied by using earthquakes, specifically those in the South Sandwich Islands and recorded in Northern Canada, passing through the earth's core on their way.

There is no shortage of South Sandwich earthquakes and many are very similar. Over the years their signature in Northern Canada has shown differences. The differences have been attributed to the Inner Core rotating at different speeds and lately the differences have been thought to be because of changes to the cores shape.

The above is a very superficial reading of the research. If you want to know more there is the BBC ARTICLE which is based on this SCIENTIFIC PAPER. The diagram below might help to understand the research.

 Jurassic Coast Trust to Close

A correspondent alerted me to this. Details can be found on THIS BBC WEBPAGE. At least the Jurassic Coast is still open. But it is very sad.

 Down to Earth Extra February 2025

The February 2025 edition of Down to Earth Extra has been published. You can download it HERE or you can read it below.

 Fish Vomit Fossilised

A correspondent sent me THIS LINK, for which I thank him. It concerns the find by an amateur fossil hunter of what turned out to be fish vomit. It consist of all the indigestible bits of what some fish had eaten. You can see bits of crinoid.

It comes from Stevns Klint which has some renown as a place where the contact between the Cretaceous and Paleogene can be seen, with its iridium enriched layer.

The specimen comes from the Cretaceous and helps us envisage life beneath the waves at that time.

The Fabulous Triassic 

A correspondent has brought THIS ARTICLE to my attention. It is from the Christmas edition of The Economist. You may have to go through some hoops to read it but you should get in without much difficulty.

And it is worth reading as it gives an overview of the Triassic AND it quotes Mike Benton!

The articles contention is that, although often overlooked, it is the period that led to the world as we know it. And it is fun to read!

 Why the Earth is Not Like Venus

At first glance the Earth and Venus should be similar and have geology with more resemblances than differences. A closer look tells us that it is a very different place.

The longest any lander has survived on Venus is 2 hours. We have been on Earth for rather longer. The surface temperature is about 465⁰C, the atmosphere is mostly carbon dioxide and there is virtually no oxygen and water.

Orbiters have used radar to look at the surface and conclude that it is mostly wrinkled plains of lava. There are lots of volcanoes and some are very large.

THIS ARTICLE will tell you all you need to know about the place; and comes to the conclusion that the crucial difference with the Earth is the lack of a magnetic field of any great strength.

Most of the lighter elements - especially hydrogen and oxygen - have been lost to space by the action of the solar wind. The atmosphere has been eroded of all its lighter components, leaving carbon dioxide and thus a runaway greenhouse effect.

The Earth's magnetic field protects the atmosphere from the solar wind. It has had a magnetic field for at least 3.7 billion years. 

Are Vast Amounts of Hydrogen Fuel Hidden Below Earth's Surface?

 

Are Vast Amounts of Hydrogen Fuel Hidden Below Earth's Surface?

The short answer is that we do not know! A longer answer can be found in THIS New Scientist Article.

A couple of emails ago I wrote about using ophiolites to produce hydrogen. Many people believe that you do not need to do that as there should be lots of hydrogen lurking below the earths surface. There is talk about quadrillions of tonnes. But so far only one deposit is known - (in Mali).

Finding other deposits is proving to be very difficult - unless they have been found and the finders are keeping quiet! We do not want to go down that rabbit hole! (A bore hole surely!)

I hope more evidence appears soon and we can stop following speculation.