Down to Earth Extra April 2023 

The April 2023 edition of Down to Earth Extra has been published. You can download it HERE or you can read it below.

 2 Nick Chidlaw Indoor Courses

The Lizard and Anglesey

Nick Chidlaw has asked me to publicise two course he proposes to run in late April. These are independent of one another: enrollees can choose to do both or either, according to their availability / interests.  

The courses will be held at Chantry Community & Arts Centre, 52 Castle St, Thornbury, Bristol BS35 1HB, UK (www.thechantry.org.uk)

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 THE GEOLOGY OF THE LIZARD PENINSULA, CORNWALL:  400 million year old crustal and mantle remnants from a closed ocean 

Saturday 22nd April 10.00 am - 5.00 pm

The Lizard Peninsula includes ocean crust rocks and upper mantle rocks that were metamorphosed in an ocean basin setting, and later obducted onto continental crust as the ocean basin closed. This closure is referred to as the Variscan Orogeny, and marks a major tectonic plate collision that affected what is now the British Isles and central Europe, notably towards the end of the Carboniferous period, about 300 million years ago. Other rocks on the Lizard formed in this ocean setting include 'turbidites' deposited from successive clouds of descending sediment, and coarser material laid down by underwater landslides. There are also some discrete igneous intrusions and slices of older crustal units present.   

No previous knowledge of geology or the area will be assumed.   

 

Tuition fee: £30.00 

Contact tutor Dr Nick Chidlaw nickchidlaw@gmail.com to enrol and for any queries. 

Deadline for course viability: Thursday 6th April. If the course has become viable (minimum of 10 enrolments) by this date, enrolments will be able to continue until 1 week before the course runs (Saturday 15th April). 

 Serpentinite rock, Kynance Cove. It was formed through alteration of rocks originating in the earth's upper mantle. 

Cross section reconstruction of the developing plate collision at the Devonian-Carboniferous boundary about 360 million years ago. 

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GEOLOGY OF THE ISLE OF ANGLESEY, NORTH WALES 

Sunday 23rd April 10.00 am - 5.00 pm

The geology of Anglesey, or Ynys Mon, is of international significance, it being designated a 'Global Geopark' by UNESCO.  Much of the island is composed of Precambrian - Cambrian rocks, formed during tectonic plate collision; these include 'blueschist' rarely seen elsewhere in the British Isles, and submarine landslides containing blocks over 1 km in size. In Silurian times, copper ores were emplaced at Parys Mountain, and these have been exploited by man since the Bronze Age. Old Red Sandstone containing ancient soils, and fossiliferous rocks of Carboniferous age, are also present.   

No previous knowledge of geology or the area will be assumed.    

Tuition fee: £30.00 

Contact tutor Dr Nick Chidlaw nickchidlaw@gmail.com to enrol and for any queries. 

Deadline for course viability: Thursday 6th April. If the course has become viable (minimum of 10 enrolments) by this date, enrolments will be able to continue until 1 week before the course runs (Sunday 16th April).  

 'Pillow' structures in spilite lava. Bodorgan Formation (Late Cambrian - Early Ordovician age), Llanddwyn Bay, in the SW of Anglesey. 

The Great Opencast at Parys Mountain, NE Anglesey. Some 300,000 tonnes of copper ore are estimated to have been extracted at Parys Mountain between the mid 18th century and late 19th century. Great quantities of metallic ores remain untapped at depth in the subsurface.  

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 Venus Erupts! - or did in 1991

This story has started to appear in various places - for example HERE, HERE and HERE. All these are based on THIS ARTICLE in Science. It is well known that studying Venus is very difficult. The surface is an extraordinarily hostile environment - high pressures and temperatures.

Its surface has been mapped by radar from satellites orbiting the planet. In particular the Magellan satellite did this in the early 1990s. And some areas were mapped twice. And one of the authors of the original paper studied these, and after painstaking efforts found that one volcano showed changes between February 1991 and October 1991. And these changes are interpreted as the result of an eruption.

When you look at the images used, one is amazed and impressed at the patience and dedication of the researcher. 

No one is surprised at the idea of Venus having eruptions - it is just that there has been no evidence of an actual eruption. Venus is the most Earth-like of the planets in terms of size, mass and density. People would be surprised if there was no vulcanicity. 

One wonders why Venus is so unlike the Earth in the composition of its atmosphere. Perhaps future missions to the planet will tell us why this is so.

Maat Mons. The arrow points to the location of the volcanic vent that erupted in 1991, which is too small to show up at this scale. NASA/JPL

Predicting Earthquakes 

If you want a readable account about predicting earthquakes go to THIS ARTICLE from Nature. When I was at university we were taught that you could predict where an earthquake would occur. You could also opine about why, but, were told, never say when! Nowadays it seems that we still cannot say when.

You can get round the dangers of earthquakes by building earthquake tolerant buildings - a precaution not universally taken in Turkey in recent years.

The magnitude-7.8 earthquake in Turkey last month destroyed many buildings, such as this one in the city of Kahramanmaraş.Credit: Adem Altan/AFP via Getty

The Nature article gives a lot of information on current research so we can now tell (when there is sufficient data) when faults are likely to rupture - within a couple of years. But we are still not able to put a date on the next earthquake.

 We Are All Sarcopterygians!

A correspondent sent me THIS LINK. It concerns the transition from sea dwelling to land dwelling animals. In particular it deals with fish which had fins with bones in them - the Sarcopterygians. The evolution of tetrapods from these is well established and that leads on to dinosaurs, birds and every one of us.

The major fact of the article is the connection between walking and its expression in the genome. And tells of the little skate Leucoraja erinacea which is a fish which often walks on the sea bed. (The video in the article about this little fishie is fascinating!)

The genome of this fish has been examined and the bits of it used when it walks are found to be the same as those of mice!

So the "software" for walking was evolved many millions of years ago and is still used whenever I walk!

3D rendering of the tiktaalik, an extinct walking fish. Dotted Yeti/Shutterstock

 Down to Earth Extra March 2023

The March 2023 edition of Down to Earth Extra has been published. You can dowload it from HERE or you can read it below.

Did Pollination Start in the Permian? 

In the Urals, in Permian rocks, insects covered in pollen have been discovered. That is known, everything else is speculation. A correspondent emailed me about THIS ARTICLE, which is based on THIS PAPER. (Unless you pay £17, only the abstract is available - unless you are an FRS!).

The pollen comes from gymnosperms - flowering plants came much later. Were the wee beasties involved in pollination - no one can say. But it is very interesting.

A tillyardembia fossil with an enlarged area showing pollen attached to its body. Photograph: Alexander Khramov/Russian Academy of Science/PA

 Greenest Hydrogen is White Hydrogen!

Hydrogen comes in a rainbow of varieties. "Grey" hydrogen comes from reforming methane; "grey" can become "blue" if the CO (carbon monoxide) byproduct of grey is stored underground; "green" is produced from water by carbon-free renewable electricity.

Hydrogen formed from solar powered electricity is "yellow"; "red" is made chemically from biowaste; "black" by coking coal using steam; "pink" by nuclear powered electrolysis; and "turquoise" from methane, leaving only solid carbon, using renewables and - probably - magic!

You can learn all this by reading THIS ARTICLE which was based on this LONG ARTICLE 

But best of all is "white" hydrogen - hydrogen produced from the earth without any processing. This was thought not to exist - mainly because no one was looking for it! Petroleum companies did not analyse for hydrogen when they tested gas produced. And hydrogen is not found in the sorts of rocks petroleum companies were drilling.

Eventually it was realised that hydrogen was coming out of the earth. And as people began to look for it the more was found. Where does it come from? - That is still being worked on. The following diagram tells all (as far as we know).

There is a lot of interest in hydrogen exploration. Will it save civilization? Watch this space!