Kilauea Puts on a Spectacular Show!

Many of you will have seen some of the videos from the Big Island of Hawaii. Kilauea has been fountaining lava hundred of metres into the air in some of the most spectacular footage I have ever seen.

THIS YOUTUBE VIDEO has a geologist explaining the geology, which is almost as fascinating as the the sight of the lava fountaining.

 Lake Water Mixing is Slowing - Should we be Worried?

I came across THIS ARTICLE in Quanta magazine and found it very interesting. The bit which caught my imagination was the method of measuring water clarity. 

The disc pictured above is lowered into the lake and when it disappears from the observers sight - that is the Secchi depth.

The lake with the longest history of clarity readings is Crater Lake in Oregon in the USA. And lately the lake has been getting clearer. And that is the result of less mixing of the lakes water.

Lake water mixing is the result of many things, but one of them is the surface water becoming warmer, therefore lighter and less likely to descend and mix. In winter the surface water cools and therefore sinks and mixes. But, in many places this no longer happens.

And as a result the water at the bottom of lakes becomes depleted in oxygen.

In Crater Lake another result is that the warm surface layer becomes thinner - the energy (wind) needed to mix the surface layers becomes greater and it does not happen. The thinner surface layer means less phytoplankton and clearer water.

The article goes on to look at other lakes, especially Lake Tahoe, which used to be very similar to Crater, but shows more signs of deterioration. 

This is an article well worth reading.

 Down to Earth Extra December 2025

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

 Down to Earth Extra November 2025

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

Jurassic Lives Uncovered

A little while ago I was complaining about a lack of local geological stories. Then two come along at once! You have probably read all about them yourselves but just in case, here is what I have found out.

First of all - Xiphodracon goldencapensis - is an 185 million year old icthyosaur found in 2001 in the cliffs between Charmouth and Seatown. I read about it first in a BBC ARTICLE and, later, tracked down the ACADEMIC PAPER which describes the beastie in great detail. The lead author of this paper, Dean Lomax, is based at Bristol and Manchester Universities.

The holotype and only known specimen of the hauffiopterygian leptonectid, Xiphodracon goldencapensis (ROM VP52596) from Golden Cap, between Charmouth and Seatown, Dorset, UK. The skeleton is exposed in ventrolateral view. The skull has been fully prepared free of matrix whereas most of the skeleton is still in matrix. The left (upper) forefin has been prepared so that it is three-dimensionally preserved and projects upwards. Scale bar represents 20 cm.

The animal has been identified as a new species and dated as being from the early Pliensbachian. This is a time from which few icthyosaur fossils have been collected and this makes the find of some importance.

And secondly - a dinosaur trackway found. The BBC has produced a YOUTUBE VIDEO about the discovery of a very long sauropod trackway in an Oxfordshire limestone quarry. One suspects that a documentary is on its way.

The trackway is over 220m long and is thought to have been made 166 million years ago. The dinosaurs were land animals but they were walking in shallow sea water - there are marine fossils next to the footprints. 

Anne Bronte's Rocks

 Anne Bronte's Rocks

A correspondent, in reply to my remark that it was becoming difficult to find things suitable for this blog, sent me THIS LINK to the journal "Bronte Studies". This journal does not usually find its way to the top of my reading list but it takes us back to a time when being educated meant being interested in everything!

If you go to the Bronte Parsonage Museum you will see Anne Bronte's collection of stones.

 Anne Bronte’s collection of stones, as displayed at the Bronte Parsonage Museum. Courtesy of the Bronte Society.

The collection has been studied and found to be largely carnelians - a form of the silica mineral chalcedony. There is also a piece of flowstone and a couple of agates. The stones could not all have come from one site and they seem to have been deliberately chosen.

The article suggests that Scarborough is the most likely place where Anne collected her rocks. Her work as a governess took her to the place. She may have collected them herself or purchased them from a lapidary, of which there were several within the town. Some of the carnelians are of high quality and suggest that Anne knew what she was doing while making her collection. She certainly valued her collection enough to take it back to Haworth.

(You have probably noticed the plethora of links in this post. This is a new feature of Blogger, the app which I use to write this blog. I suspect that I will turn it off in future posts.)

 Air Balloon Geology

Recently a subscriber to this blog asked "I wonder if you know of any geological treatise on the A417 "Missing Link" at the Air Balloon pub site? ..... They plan to keep the strata exposed for all to see when driving past, like has been done on the Cirencester dual carrageway."

Well, the short answer is that I do not know what is happening there. If you do, send me the details HERE and I will pass them on. 

But the request sent me on a mission to discover what the geology is at the Air Balloon Pub. My knowledge of the place is being stuck in a traffic jam, waiting to get on to the M4 at Gloucester. And I discovered the latest addition to the BGS web site - the GeoIndex Beta.

With a little persistence I managed to produce the following map.

The original map can be found HERE.

If you click, on the original map, on a formation you get a pop-up similar to the following:-

The link takes you to THIS PAGE which tells you a lot about the Birdlip Limestone. The parent of this page IS THIS - the Lexicon of named rock units of the BGS.

I used this to name several of the formations on my Air Balloon map.

To search the Lexicon use the Computer Code given in the pop-up, or the Preferred Map Code. (This the code in the last line of the rock names I have put on my Air Balloon map.)

So now I know a great deal more about the Air Balloon Pub area and know how to access a vast amount of Geological Knowledge, but I still cannot answer the question which started this search!