Thursday, 2 July 2020

Tomotectonic Analysis of Western North America

Tomotectonic Analysis of Western North America

This is the first time I have come across this term. It means a tectonic plate reconstruction using both mantle and geological evidence. 

The paper which introduced me to the term has not yet been published but a PDF form is available HERE. The amount of information used in this paper is phenomenal. And it shows when you look at the animation below. It is this which first attracted my attention. Watching the continents dance is always fun!

You can see a full size version on THIS PAGE. Scroll to the bottom, click on Supporting Information and the on either of the video files.

I have glanced at the paper and quickly realised that you need to be a specialist to criticise it. And that is not me!!! Enjoy the animation.

Wednesday, 1 July 2020

Mesozoic Insects Show Their True Colours

Mesozoic Insects Show Their True Colours

A correspondent sent me THIS LINK. It tells of some remarkably well preserved insects of mid-Cretaceous age. They have been found in amber, recovered from a mine in Burma. Not only have the forms of the insects been preserved but also their colours. 

The colours are structural colour, formed by fine structures on their bodies which are small enough to interfere with visible light. And it is likely that the colours we see are the same as the colours the insects had in life. The original article (and more pictures) can be found HERE.

It's the Asteroid That Did it!

It's the Asteroid That Did it!

From a twitter feed, a reader of this blog, Anthony Brook, produced THIS PDF file. It concerns a paper which looks at the causes of the K/Pg extinction event. (This was the K/T event in my youth.) Among the authors are two from Bristol's School of Geographical Sciences.

They discuss whether the Chicxulub asteroid or the Deccan traps were the culprit. They use climate modelling of a complexity which I can appreciate, if not understand.

The conclusion they reach is that Deccan volcanism would have led to cooling but have left enough equatorial habitats for dinosaur survival. Indeed the CO₂ produced by the volcanism would have mitigated the effects of solar dimming.

Asteroid impact, however, would be sufficient to remove all dinosaur friendly habitats. They suggest that the Deccan volcanism might have made things rather better! Global warming, due to CO₂, might be a good thing here!

Since the production of the twitter feed the actual publication has now emerged. You can get it HERE. Thanks to Anthony Brook for bringing this to my attention.

Geologic (A) and paleontological (B) records of the K/Pg mass extinction. Paleothermometer (A) showing the Deccan-induced warming with the two main episodes of volcanism highlighted by the black arrows and symbols of volcanoes. The last phase extends beyond the end of the Cretaceous, characterized by the bolide impact in Chicxulub. Fossil remains of non-avian dinosaurs (body fossils, egg fragments, and nesting sites) occur throughout the whole stratigraphic record of prolonged volcanism episodes (dinosaur silhouettes). Numbers represent upper Maastrichtian dinosaur bearing localities, mapped on a late Maastrichtian paleogeography in B. 1, Hell Creek Formation (United States); 2, Lameta Formation (India); 3, Tremp Formation (Spain); 4, Phosphorite beds (Morocco); 5, Marilía Formation (Brazil); 6, Nemegt Formation (Mongolia). Dinosaur silhouette image credit: Phylopic/Jack Mayer Wood, which is licensed under CC BY 3.0.

Saturday, 27 June 2020

Down to Earth Extra - July 2020

Down to Earth Extra - July 2020

The latest edition is available HERE.

Or you can read it below.

Friday, 26 June 2020

GeoConservation Newsletter

GeoConservation Newsletter

The latest edition of the GeoConservation NewsLetter has been released and you can get it HERE. Or you can read it below. It is packed (in several senses!) with material. There is a lot to read. A thought for the editor - not many people are going to print the newsletter, so waste of paper is not a consideration. Why not put more white space - blank lines between paragraphs, bigger type, spread things out.

But well worth reading.

Monday, 22 June 2020

Quick Clay - a Reason to Avoid Norwegian Farm Holidays!

Quick Clay - a Reason to Avoid Norwegian Farm Holidays!

The Landslide Blog has come up with two fantastic videos from Norway. THE FIRST is of a recent landslide at Alta in northern Norway. Nothing much happens until 2 minutes 20 seconds in and then be amazed. 

Apparently there are copyright issues with the video above. But you can see the same video HERE

The SECOND VIDEO is much older - and it shows - but it gives the scientific explanation of Quick Clay Landslides. About two minutes in they give a vivid illustration of solid clay becoming liquid.

An intact block of quick clay being loaded to beyond its strength.

Failure of the block of quick clay being loaded to beyond its strength.

Remoulded behaviour of the block of quick clay being loaded to beyond its strength. No water was added! But it acts as a liquid.

Fossil Reptiles not Picky Eaters

Fossil Reptiles not Picky Eaters

Not a surprising headline but a difficult one to verify. But a PhD student at Bristol has done so for a couple of species. A correspondent brought THIS ARTICLE to my notice, for which I am very grateful.

The student, Sofia Chambi-Trowell, CT scanned skulls of 200 Ma rhynchocephalians and worked out the bite forces and pressures their jaws could produce. And found them capable of eating the small mammals, reptiles  and bugs in their environment. 

The fossils came from Permo-Triassic fissure deposits in the Carboniferous Limestone.

Clevosaurus hudsoni could eat crunchier prey than Clevosaurus cambrica and this mirrored what was happening with the areas mammals which had been studied earlier. Presumably the two species could live side by side without encroaching on the others diet.

Two species of the lizard-like reptile Clevosaurus hunting their preferred prey; Clevosaurus hudsoni feeding on a crunchy beetle (top) and Clevosaurus cambrica (bottom) feeding on a softer insect. Image Credit: Sofia Chambi-Trowell

Mapping the Sea Floor

Mapping the Sea Floor

A correspondent has emailed THIS LINK which tells us of the progress being made in mapping the sea floor. So far 19% of the oceans floor has been mapped with a resolution of 100m or better. 

There are a host of reasons to map the sea floor, many commercial but also scientific. The article discusses the many ways it is being done. The idea of a fleet of robotic surface vessels sounds very odd but may work well. 

Mapping the sea floor is not high profile but will over the years prove to be invaluable.

The black (non-continental) areas are where coverage is poor.

Thursday, 11 June 2020

Scottish Millipede - World's Oldest Bug!

Scottish Millipede - World's Oldest Bug!

A correspondent sent me the link to THIS ARTICLE which is based on THIS ARTICLE. But you need to pay to see the latter in full.

The interest in the find is that molecular clock calculations suggest that this millipede (an Arthropod) should have appeared at 500Ma - 75Ma before it actually did. 

Obviously dates are important and the date of the specimen was found using the U/Pb method on zircons extracted from the sediment which contained the millipede. (With great care - pin glued to a pencil tip!). This was done for three UK sites. 

The sites and ages were:- 

Kerrera         425Ma    (Kerrera is near Oban)

Ludlow          420Ma

Cowie            414Ma   (Cowie is near Stonehaven)

The Rhynie Chert, which contains a diverse arthropod fauna, is 407Ma.

Google was able to supply this photo of a millipede said to be 425Ma.

Thursday, 4 June 2020

Dinosaur Diet Revealed!

Dinosaur Diet Revealed!

A correspondent has sent me a link to THIS ARTICLE. It tells of a nodosaur, a type of ankylosaur, which fell into a stream and drowned. Its body was preserved in what is now an oil sands mine in northern Alberta, Canada.

Study of its remains revealed its stomach and that the contents were undigested and could be identified. It had dined on ferns (with spores), twigs, leaves and lots of charcoal. It had not eaten the widely available cycad and conifer leaves. The charcoal suggests that a forest fire had occurred recently.

I presume this is a nodosaur

Wednesday, 3 June 2020

Snowball Earth and the GOE

What Caused the First Snowball Earth?

THIS ARTICLE discusses the effects of the Great Oxidation Event (GOE). Did it occur before or after the first snowball earth? We know both occurred about 2.4 billion years ago.

The method used in this study is the ratios of sulphur isotopes. Post GOE these are stable and predictable but before this photochemical reactions in the oxygen-free atmosphere are preserved as unpredictable sulphur isotope ratios. So pre GOE unpredictable; post GOE predictable. Therefore measure sulphur ratios and find the date of the GOE.

Using cores of sedimentary rocks, of the appropriate age, from the Kola Peninsula, the researchers in St Andrews, pin the GOE to a 70 million year interval between 2.50 and 2.43 billion years ago. In this context, a very short period!

This is before the snowball Earth deposits. It is postulated that rising oxygen levels lowered methane levels, weakening the greenhouse effect, and leading to a major period of glaciation.

If we looked at the Earth before the GOE would we have thought it a good prospect for habitation? And removing greenhouse gases from the atmosphere is not without risk!

Postgraduate Diploma in ‘The Geology of Northern England’

Postgraduate Diploma in ‘The Geology of Northern England’ 

From various sources has come the following intelligence:-


The Postgraduate Diploma in ‘The Geology of Northern England’ programme, from Dr Annette McGrath.

To find out more about the PG Dip programme, please:

·         Visit the website here

·         Attend our Virtual Open Day on the 4th of June

·         View our flyer (attached)

·         … or alternatively please feel free to directly respond to me, Amanda Pauw, Postgraduate Administrator at this email with any queries or to the Programme Leader, Dr Annette McGrath at


Dear Sir or Madam,

I hope this email finds you safe and well in these difficult and challenging times, and that you are managing to keep yourself suitably occupied and distracted.

On that note, I am writing to you now to raise awareness of the online Postgraduate Diploma (PG Dip) in ‘The Geology of Northern England’, run by the Centre for Lifelong Learning at the University of York, as I feel that it will be of interest to you. This part-time, two-year innovative programme is run entirely by distance learning via a virtual learning environment, and enables like-minded people to meet and engage online in a safe, friendly and flexible environment. The PG Dip programme has been going from strength-to-strength since its inception in September 2015, and we are currently taking applicants for a September 2020 start.

From the spectacular igneous geology of the Lake District World Heritage Site and Northumberland National Park and AONB, to the fascinating sedimentary geology of the Yorkshire Jurassic ‘Dinosaur Coast’ and the mineral wealth of the Pennines…. the North of England has an incredible geological history, spanning almost 500 million years.

Concentrating mainly upon the geological evolution of northern England, you will analyse and interpret key geological features and concepts to integrate regional knowledge into the interpretation of larger scale Earth processes and structures. You will assess the region’s importance in current and historical Earth science controversies and study human interactions with the rocks and landscapes of northern England from the Stone Age to the present day.

Whilst your studies will focus on the geological history of northern England there are also countless opportunities to focus your own reading and research on to other areas of the UK (and the wider World) – and you will be able to learn more about your own home region too, if desired.

The PG Dip also covers other significant and topical aspects of geology that are not necessarily encountered in northern England: for example the fascinating North Atlantic Igneous Province (aka the British Tertiary Igneous Province); the sudden global warming and extinction event that resulted in the Palaeocene-Eocene Thermal Maximum (PETM)… and much more.

The online format offers you the opportunity to study in your own home, at your own pace, whilst also being extensively supported by an experienced Lecturer. You will also have the opportunity to participate weekly (but to suit your own lifestyle and time constraints) in a lively, supportive and scholarly online community. The programme also includes a mandatory residential week* at the beginning of each year, which provides an opportunity to meet the Lecturer, network with fellow students, engage in class-based study activities and spend time out in the field, examining Yorkshire’s geology up close. (* Please note that the face-to-face element of the residential week course is subject to the Covid-19 restrictions at the time, and will be in line with wider government and university advice and policies).

The PG Dip programme offers graduates a strong foundation for any kind of vocational or geological/non-geological career path. On completion of the programme, graduates are well-prepared for geological careers within research, academia, teaching, museums, archives, government organisations or research councils. Graduates are also well-equipped to pursue employment within industry, such as the oil, gas and petroleum sector, natural hazards, the groundwater and hydrogeology industry, environmental geology and contaminated land, mining, quarrying, engineering geology and construction companies.

Should your circumstances change, you can end your studies after one year and graduate with a Postgraduate Certificate. You're also able to carry credits on to a Masters course at the Open University if you wish to take your studies further.

The programme starts in late September, concurrent with each new academic year – places are limited to ensure a constructive atmosphere for discussions.

So apply now to uncover the extraordinarily diverse landscapes and geological history of northern England!

Best Wishes – and stay safe.



Dr Annette McGrath

BSc Hons, ARSM, MSc, PhD

Associate Lecturer and Programme Leader Postgraduate Diploma in ‘The Geology of Northern England’

Honorary Research Fellow University of Leicester:

Geology Tutor Higham Hall Adult Education College:

Email:     Twitter: @AnnetteMcGrath7 

Monday, 1 June 2020

Broken Ozone Layer Caused End Devonian Mass Extinction

Broken Ozone Layer Caused End Devonian Mass Extinction

A correspondent brought THIS ARTICLE to my attention. It reports on field work in Greenland and Bolivia by scientists from Southampton University School of Ocean and Earth Science. 

They looked at spores and discovered that they were malformed, indicating damage by ultra-violet radiation. Today the ozone layer protects us from such radiation and they surmise that today's conditions are similar those of the late Devonian. A similar collapse of the ozone layer could have deadly consequences.

Two Short Geological Field Trips with Nick Chidlaw

Two Short Geological Field Trips with Nick Chidlaw

Nick Chidlaw is offering to lead a couple of field trips following all the Covid-19 Rules. All the details are below. Responses are required by 3rd June.


Dear All,
As you know, the Westminster and devolved UK governments have begun various measures to bring some relieve to the continuing social and economic lockdown. This varies across the countries of the UK, and is being implemented with necessary caution: a return to full lockdown will be essential, either locally or nationally, if C-19 cases begin to rise again.
Lockdown has been quite an ordeal for many people, not least those who enjoy being out in the field, such as students and tutors of geology. I have been very pleased that the ‘Lockdown Geology’ quiz I offered in late April had a good response, and the work received was of very high quality. I am also very gratified that the two distance–learning courses I’ve proposed recently have generated an encouraging response, and hopefully both of these will become viable by their June 10th deadline.
You’ll have heard that from this coming Monday (1st June), in England, groups of up to 6 people from as many households – practising social distancing – will be permitted to meet in outside locations.
I am happy to take this opportunity for us to get out into the field again and do some geology, albeit in a limited way.
I am proposing the following:
*    Cleeve Cloud Short Geological Field Trip    
*    Selsley Common Short Geological Field Trip 
‘Cleeve Cloud’ is close to the crest of the Cotswold escarpment to the east of Cheltenham, and has both excellent extensive rock exposures (a variety of limestones, Middle Jurassic) and dramatic views across the Severn Vale to the varied landscapes of the Welsh Borderland, including the Forest of Dean and the Malverns. The jpg attached shows part of the exposures at Cleeve Cloud. 
Selsley Common is located on the crest of the Cotswold escarpment near to the town of Stroud, has numerous rock exposures in small disused quarries (a variety of limestones, Middle Jurassic), and excellent views westwards somewhat similar to those seen from Cleeve Cloud. The jpg attached is of a Google Earth oblique image of Selsley Common, showing its pitted surface from old shallow quarry workings. The most informative exposure is away from these, close to the wood in the top right part of the image. Stroud is off to the left (north) side of the image.   
Both these locations are very suitable for ‘social distancing’ – they are provided for by ample extensive parking spaces, and open, almost treeless ground where people can spread out easily and not be restricted (such as on narrow footpaths bracketed by fences, walls or trees). 
I have run field trips to these locations many times in the past, and know them well.  
The aim of these short field trips is to provide some field geology for those who are keen to get out again, while exercising at all times appropriate measures to keep themselves and others safe re. C-19. Anyone who would rather not attend in view of their concerns regarding C-19, I would certainly appreciate this.
No fees would be required to attend these short field trips.  
There would be no handouts prepared for attendees on these field trips – it would be a case of me describing the geology from my own notes, and pointing out features in the field; attendees could bring their own notebooks / pencils to record details, take photographs and collect any specimens they wish (I would break up any loose rock material for you to collect from).
There would be no insurance cover for attendees on these trips: the insurance cover I usually have for my courses and trips is to be renewed once these can run again.  Attendees would be advised to wear hard hats when close to overhead rock exposures; ideally they would bring their own, but I can lend some to those who do not have one. Summer clothing would be worn, so bringing a windproof top or sweater would be a good idea in case needed at any point. Suitable headwear (e.g. bush hat) when away from rock exposures would be useful for protection from strong sunshine. Suitable footwear with good tread and ankle support would be advised.
On the field trips we would, as normally, follow good Health & Safety practise. In the unlikely event of injury, both field localities have easy access for an ambulance, should this be necessary. 
Each trip would have, as necessary, only 5 attendees. Trips would be repeated in order to accommodate those who may wish to attend. 
We would meet at a stated parking location (I will email sketch map and postcode for satnav), and from there walk to the start of the rock exposures to be examined. For Cleeve Cloud, the walk would be approximately 20 minutes there, and 25 – 30 minutes back. For Selsley Common, the walk to the first exposure is less than 5 minutes, and c. 10 minutes back from the last exposure. Walking surfaces are well-trodden footpaths and grassy common land with a mix of undulating ground and locally steep slopes.   
Because of the lockdown, there will be no opportunities to visit pubs for refreshments and use of their facilities. Any public loos will be locked to prevent the possibility of C-19 infection. Ideally, aim to use your loo at home before you travel to the field area. We can find ‘al fresco’ opportunities if necessary.
Bringing your own refreshments, such as flask of coffee or tea, fruit juice, water would be a good idea.     
The Cleeve Cloud trip would extend for 3 hours (includes walking time from the car parking area and back).
The Selsley Common trip would extend for 3 hours (includes walking time from the car parking area and back).
Dates in June
We are currently enjoying an extended dry warm sunny spell, and the dry weather (becoming more cloudy and a little fresher) is forecast to continue for at least a week or two; some minor showery spells might develop. 
My thinking is we therefore act soon, to take advantage of the continuing dry spell.
Weekday afternoons and, particularly, evening times would be useful, to minimise the numbers of people who might be using the car parks and walking in the areas of interest.  Sunset is well after 9 pm now. 
Arrival times at the car parks would be from 1.40 pm for the afternoon trips and from 5.40 pm for the evening trips.  
Date Options:
DATE                   AFTERNOON 2 – 5 pm                        EVENING  6 – 9 pm 
Friday 5th              Selsley Common trip                              Cleeve Cloud trip  
Monday 8th            Selsley Common trip                              Cleeve Cloud trip   
Tuesday 9th            Selsey Common Trip                              Cleeve Cloud trip    
Choosing a date
Using the above 3 dates and offering both field trips on each day, potentially caters for a maximum total of 30 people (assuming no one attends more than one trip).  Additional dates later in June or further into the summer could be organised if there is sufficient interest.  
If you would like to attend one of these field trips, let me know which location you would prefer to attend, and on which date. Give me your first choice of location / date, and your second choice of location / date, and I will aim to provide as many people with their preferences as possible.
Necessarily, I will need to operate on a first come, first served basis. If there is a good response to this proposal, and you find you cannot be catered for, I will organise some new dates for later in June or beyond to see what we can sort out.  
Please get back to me by next Wednesday (3rd June), and I will organise the trips according to the level of response received.
Any queries, do let me know.
I hope this proposal is of interest to you, and to hear from you soon! 
Nick C.

Friday, 29 May 2020

Down to Earth Extra - June 2020


The latest edition is available HERE

Or you can read it below.

Wednesday, 27 May 2020

Strong Poison - in the well

Strong Poison - in the Well

I came across Lord Peter Wimsey and arsenic in Dorothy L. Sayers novel "Strong Poison" which I strongly recommend - the novel, not the arsenic. THIS ARTICLE is much less entertaining but very informative. 

What started as a good thing became a tragedy. Providing water from drilled wells stopped people becoming ill from gastro-intestinal infections. But, over time, signs of arsenicosis appeared. 

Why arsenic got into the water is far from obvious. The article explains the complex chemistry involved - goethite (containing Fe-3 and other stuff including arsenic) in reducing conditions breaks down to Fe-2 and releases its arsenic. Fascinating and deadly chemistry!

Well worth reading and here is a map showing where it is not safe to drink the well water.

Modelled global probability of arsenic concentration in groundwater exceeding 10 μg l-1. Click to display a larger map in a separate browser tab. (credit: Podgorski & Berg; Fig 2A, with enhanced colour)

Mary Anning - her story in an unusual form

Mary Anning - Her Story in an Unusual Form

I came across THIS and thought most of you would like it. Turn up your loudspeakers

Saturday, 23 May 2020

Edenville Dam Breach

Edenville Dam Breach

One of my favourite blogs (The Landslide Blog) has 3 very interesting articles about the the breaching of this dam in Michigan USA.
The FIRST gives the news and the information that its licence had been withdrawn.

The SECOND has a video showing the failure of the dam. It is this which drew my attention.

And the THIRD discusses what happened and the consequences. The author suggest many similar dams will need to be looked at as global warming is changing weather patterns and higher rainfall may be greater than many dams can cope with. 

Tuesday, 19 May 2020

Martian Mud Flows

Martian Mud Flows

There are features on Mars that could be mud flows or lava flows. Until this is settled, perhaps (but unlikely) by a geologist with a hammer, speculation continues. And to provide some facts for the speculation we have THIS ARTICLE (brought to my attention by a correspondent) which describes experiments which look at how mud acts in a Martian environment.

In the low pressure of Mars's atmosphere mud acts like pahoehoe lava and looks like it also.

The initial article can be found HERE.

A suggested mud flow on Mars spied from orbit. A geologist on the ground could tell for sure.

Friday, 15 May 2020

Has Metamorphism Always been the Same?

Has Metamorphism Always been the Same?

THIS VERY INTERESTING ARTICLE follows the debate whether metamorphism has always been the same. The minerals in a metamorphic rock can tell you its temperature and pressure history. 

It has long been suspected that the average T/P conditions revealed by metamorphic rocks have varied over geological time, this article discusses A RECENT PAPER which tries to put some numbers to this speculation. And also A DISCUSSION of the paper.

At the heart of the discussion is thermobarometric data - derived from mineral assemblages which indicate the temperature and pressure at which they were formed. The 564 data points are, as one would expect, not evenly scattered through time. And clusters of data points show a wide scatter of T/P. 

But the original authors manage to extract a smooth curve showing that T/P lowered with time and suggest this is linked to the development of modern plate tectonics. 

The author of the discussion thinks the lowering of P/T is due to a fall in mantle temperature. 

All this is far above my competence - I leave you to read the articles and decide for yourselves!

The latest division in pressure-temperature space of different styles of metamorphism (colours) and the main mineral equilibria (dashed lines) that define them. Note the three T/P lines. Did early rocks follow the 30℃/km line and later ones the 10℃/km line? - very roughly speaking and using averages and with all sorts of caveats!

Peter Cawood’s ‘take’ on the relationship between tectonic development and other important variables in the Earth-system with the estimate by Brown et al. of the mean metamorphic T/P (‘thermobaric’) variation through Earth history

Footnotes May 2020

Footnotes May 2020

Footnotes, the newsletter of the Wessex Branch of the Open University Geological Society, is available for download HERE.


And, keeping the correct distance apart, read it below!

Sunday, 3 May 2020

Stonechat Magazine

Stonechat Magazine

A correspondent has brought this magazine of the Horsham Geological Field Club to my notice and now I bring it to yours! 

If I edited a magazine as good as this I would be very proud! Read it and Marvel!

You can get it HERE. Or read it below.

Thursday, 30 April 2020

Down to Earth Extra - May 2020

Down to Earth Extra - May 2020

The latest edition was sent to me in 2 parts. Get Part 1 HERE and Part 2 HERE.

I have combined the parts and you can get the complete version HERE.

Or you can read it below.

Tuesday, 28 April 2020

Geologic Map of the Moon

Geologic Map of the Moon

A frequent correspondent has sent me THIS LINK. It introduces a newly released Geologic Map of the Moon produced by NASA. 

NASA introduces it HERE. The download is a little slow but you can get it, in all its glory, HERE. Also, below.

Monday, 20 April 2020

Dinosaurs on Selsey Common!

Dinosaurs on Selsey Common!

Another correspondent has brought this interesting sight near Stroud to my attention. The pictures speak for themselves.

This post has created some controversy. Yet another correspondent writes:-
I love getting the updates and I like seeing art and science promoted but I have to say I am incensed by the latest offering 

Placing stones on grass seems set to become a craze and publicising it without a severe rebuke is unacceptable and can only fuel this act of utter thoughtless vandalism and conservation evil.

Environmental gems such as fescue and bent grasslands have taken millennia to establish and one thoughtless  (mindless) act will destroy the delicate grasses forever - eliminating the wild flowers which many butterflies depend upon as well as other less obvious problems. Tourists will exacerbate the problem as their footprints compact the soil making it impossible for these delicate grasses to survive. Not to mention the animals and plants living on or under the stones which will also lose their homes or die. 

I have seen stones placed onto heathland and downland before but never on this scale.  Please please let try to nip this illegal and damaging stupidity asap.

At the very least make it clear anyone making such art has a duty to restore nature, after a few minutes  - ensuring the stones are replaced EXACTLY where they were found and right way up Like the sand beach artists washed by the tide

I am sorry I am not a kill joy but the stupidity of our species knows no bounds. 
I have received a reply from the original correspondent.
I’m always amazed at the comments made by the narrower minded ‘conservationists’ who are only concerned with their own interest and point of view.   Totally ignoring the impact that all animals make on the planet - including homo sapiens!    Their comments give much cause for amusement though so they are not all bad...

Bearing in mind that this is in an old (human made) quarry where the locals for generations have created pictures and written their names in stone I can’t see the problem.     Especially as the quarry is surrounded by plenty of ‘natural’ grassland.

Keep up your good work of informing us all of events.
This blog is not the place for continuing this controversy, so it is now closed.

Saturday, 18 April 2020

Iceland Volcanoes - all the information

Information on Iceland's Volcanoes

A correspondent has sent me THIS LINK. It is a catalogue of all of Iceland's volcanoes and the amount of information is astonishing. Well worth a browse!

Thursday, 16 April 2020

Dinosaurs Overhead Underground

Dinosaurs Overhead Underground

500 metres below the Causse Méjean karst plateau, in the Castelbouc cave on the River Tarn, a scientist on a caving trip spotted dinosaur footprints on the roof of a rather large cavity. 

A scientist on a caving trip happened to spot dinosaur tracks in the ceiling of Castelbouc Cave in France. Credit: Jean-David Moreau et al./J. Vertebr. Paleontol.
The result is THIS ARTICLE based on THIS JOURNAL ARTICLE (you need to pay to see more than the abstract, unfortunately).

It seems that access is difficult and not for the likes of me, but it is reported that the tracks were made by some very large beastie, presumed to be titanosauriforms. Indeed the authors erect the new ichnogenus and ichnospecies Occitanopodus gandi, igen. et isp. nov. I suppose all the abbreviations mean something to the people professionally concerned with the matter.

Tuesday, 14 April 2020

A (Virtual) Geological Trip to the Karoo

A (Virtual) Geological Trip to the Karoo

Yet another correspondent forwarded me THIS LINK to a very interesting article mostly about Karoo dolerites and included three of her own photos. 

The Karoo is the "Fly Over" part of South Africa, between Cape Town and Johannesburg. Much of it is flat and boring but there are occasional spectacular, flat topped mountains and these are the result of intrusions of dolerite sills and dykes.

A particular emphasis of the article is the hope that dolerite intrusion has reduced the attractiveness of the area for companies looking to exploit shale gas. 

But my correspondents photos are the best for appreciating the dolerites of the Karoo.

Thaba Thabo, near Fouriesburg in the Freestate, near the Lesotho border.  A vertical dyke in sandstones has weathered out more than the baked margins - the hornfels.  Note that this is close to the contact with the overlying Drakensberg lavas, so it may have been a feeder dyke.
A thick dolerite body, which is climbing up section but nearer to a sill than a dyke., capping a hill near Harrismith in the North-east Freestate.

Top is a sill and another intrusion which not quite a dyke or a sill, which appears to have displaced the sandstone layers and bent them downwards, at the right.  There is a small dyklet feeding in to it along the fracture. On the road from Beaufort West to Calvinia in the Northern Cape.

Ordnance Survey - Things to do at home

Ordnance Survey - Things to do at Home

Another correspondent suggested this might be useful.

Thank goodness the step up challenge is over!

Severn Bore

Drone on the Severn Bore

A correspondent directed me to watch this footage of the Severn Bore as there were no surfers present! It was filmed from a drone and you can see it HERE or below. The reason there are no surfers is because of the Coronavirus lockdown. I suppose that is a positive.

Saturday, 11 April 2020

Oxford Geoheritage Virtual Conference

Oxford Geoheritage Virtual Conference

I know a lot of you are interested in our geoheritage in one form or another. Because of COVID-19 many conferences on the subject have been cancelled or postponed. So, of course, the answer is to have a virtual conference. This has many disadvantages - you cannot have face to face conversation or travel to exotic locations - but at least the conference can take place and you do not need to get out of bed! (or your preferred place for being online.)

You can read all about one being organised by Oxford Museum of Natural History HERE. If you want to submit a paper the abstract has to be in by 29th April. If you want to attend (virtually) you have to register by 18th May. And the conference starts on 25th May.

This sounds very good for the person with a casual interest - no cost for travel, accommodation, food etc.

Monday, 6 April 2020

Coronavirus - Seismologists Notice Something

Coronavirus - Seismologists Notice Something

A correspondent brought THIS and THIS to my attention. They both record that lockdowns imposed as a result of the Coronavirus outbreak have reduced the amount of seismic noise which reduces the sensitivity of seismometers located in urban areas. Obviously not earth shaking news but still very interesting!

Saturday, 4 April 2020

Footnotes in a Time of Virus

Footnotes in a Time of Virus

The Wessex Group of the OUGS is one of the most active and this continues in the present lockdown. 

For all of you looking for something geological to do they have produced a special edition of Footnotes, their rather well produced Newsletter.

You can get it HERE, or read it below.

Wednesday, 1 April 2020

Slow Earthquakes

Slow Earthquakes

I had heard of such things but did not know much about them, so I was interested in reading THIS ARTICLE. After reading the article I realise that calling them earthquakes is dramatising something with no drama at all! 

An earthquake releases a lot of energy very quickly. A "slow earthquake" can release the same amount of energy but over a period of months or even longer. Is a slow earthquake somewhere between rocks moving steadily and moving in earthquakes? Can a slow earthquake trigger a catastrophic one nearby?

What makes an area have slow earthquakes rather than a catastrophic one? The author (from Cardiff) has been working in New Zealand where the Hikurangi subduction zone off the south eastern coast of the North Island demonstrates slow earth earthquakes in a conveniently shallow and accessible place. 

He hypothesises that the very variable seafloor rocks and sediments may have something to do with it. Also the presence of seamounts, pressurised fluids decreasing frictional resistance, seafloor roughness and other things might be involved. Obviously we are in a phase of looking for a cause.

Out and About - on Mars

Out and About - on Mars

A correspondent emailed me THIS LINK and it is wonderful. I make a lot of panoramas with my photos but they pale in comparison (on at least two levels - quality and location!) with this one. Look on it and wonder!