Help please - Saltford railway path - 2nd, 3rd October

Excavation work on the Railway Path at Saltford starts on the 2nd & 3rd
October.  I had hoped to have a few people to assist.
The most important thing is that there are adequate helpers to work with the
public so that we avoid anyone being crushed by the digger but it will also
provide an opportunity to follow the progress of the dig.  The warm weather
looks to continue in our favour.
If you know of anyone who can help - please get them to give me a call
(01373 474086) or email
A few hours here and there will help enormously by giving others a break and
providing company.  It should be a really interesting project with the potential of uncovering some really interesting fossils/geology.

New Information Board on Two Tunnels Greenway

A new geology information board has just been unveiled on the Two Tunnels Greenway in the cutting on the south side of Combe Down Tunnel.

The board depicts:-
- the rock formations of the tunnel and the surrounding area
- some history of how the rock was commercially quarried and mined
- the work of ‘the father of English geology’ William Smith
- the former Somerset and Dorset Railway which provided the track-bed upon which the path is built
Professional input is from Avon RIGS Group members Simon Carpenter and Andrew Mathieson.

Outcrop - another west country geology blog

Have you seen Outcrop, Avon RIGS group blog? The Group's aim is to identify, survey, protect and promote geological and geomorphological sites in the former County of Avon - the modern unitary authorities of Bath and North East Somerset, Bristol, North Somerset and South Gloucestershire. RIGS are selected for their educational, research, historical and aesthetic value.
There is a live link to Outcrop on the right-hand side of this blog so you can always see what is happening in the west country.

Outcrop - The Blog of the Avon RIGS Group

Click here to see the new Avon RIGS blog.

Gordano photograph - apologies

This photograph was reproduced in the post of 28th September without full acknowledgement. It is Gordano Valley, 2006 and was taken by Martin Boulton.

Avon RIGS

Please check out the new Avon RIGS website - click HERE. The pdfs of the South Gloucestershire geology booklet and all the information panels installed in that Council area, can now be viewed and downloaded. The illustration shows the panel at Aust Cliff.

Outcrop - Newsletter of Avon RIGS Group

Have you seen the latest edition of Outcrop? Its the newsletter of the Avon RIGS group and is full of information. The autumn issue has excellent articles on the Gordano Valley, a palaeoenvironmental archive, and news of the fantastic new dinosaurs coming to Bristol. Three Scelidosaur skeletons are soon to be displayed at the City Museum.

Talking of museums - - Outcrop has a list of museums with geology displays in the former County of Avon. These have been added to the right-hand side of the blog. Please let me have a list, via 'comments' of all the others in our area and I will add them.

To receive your FREE copy of Outcrop, please contact the Bristol Regional Environmental Records Centre (BRERC) - email.

A Journey across 400 million years

This new publication by Avon RIGS is excellent and tells the story of the geological history of South Gloucestershire, spanning some 400 million years.

Three 'must see' sites are mentioned, with grid references, Aust Cliff, Huckford Quarry Local Nature Reserve and Wick Golden Valley Local Nature Reserve. There are 6 new information boards in the area and 5 other sites of interest are mentioned.

The story goes from the oldest limestones and lavas through mountains and coral seas to tropical forests to deserts and back to the sea again. The text is well illustrated featuring diagrams, maps, fossils, photos of what you will see and impressions of what the area looked like in the past. The booklet concludes with a generalised geology map. It is free and can be obtained from the Avon RIGS group.

All Sites of Geological Interest in Avon

Did you know that in Bristol City Museum, there is a CD describing all the sites of geological interest in the old Avon area (Bristol, North Somerset, Bath & North East Somerset and South Gloucestershire). Eventually, it is hoped to publish this on the Museum's website.

Volcanoes and Coral Reefs in South Gloucestershire

Yesterday I spent my day looking at lava which flowed over the Tortworth area about 425 million years ago when this bit of the Earth's crust was about 30 degrees south of the equator.

Later we moved into a warm, shallow sea where I collected about 20 little horn corals, Pycnactis (as illustrated), only about 3 cm long.

Of course, I was on the Bath Geological Society's field trip, mentioned in my post of 6th May. It was an excellent trip, very well researched and organised. It was led by an expert on the geology of the area, a member of both the Bath Geological Society and of the Avon RIGS Group. The leader's car boot was full of beautiful specimens he had collected previously from the sites. He had specimens of all the creatures shown in the cartoon - the tabulate 'chain' coral, Halysites, trilobites, crinoids and brachiopods. The sea was teeming with life but there was virtually nothing on land; no trees, no flowers, no grass and certainly no animals. At least the rocks would have been well exposed.

New RIGS sites in South Gloucestershire

Recently the only known exposure of the early Devonian (Downtonian) Thornbury Beds in the outskirts of Thornbury has achieved RIGS status. It is a small roadside stream bank showing the maroon sandstones typical of this formation. They are about 410 million years old and were deposited in desert conditions when 'Britain' was at about 23 degrees South.

A second recently identified RIGS site is near the castle and Parish Church where a low cliff displays the Triassic Dolomitic Conglomerate as a series of clastic flows fining from south to north. Some of the clasts are boulders 1 metre across. You can imagine the power of the flash flood that moved these. It's called 'Thornbury Rock' not to be confused with the sugary stick. It is about 230 million years old and was deposited when 'Britain' was again in desert latitudes at about 23 degrees North.

A third RIGS is in the Tortworth Inlier and is of the Silurian Wenlock Limestone. It's in a ditch 2m x 1m but it does have very good fossils, including stromatolites (algal mats). This limestone is about 425 million years old and was formed in a warm sea when 'Britain' was at about 30 degrees South. This site is on private land and will be visited by members of the Bath Geological Society on their field trip on 12th May.