Monday, 31 August 2015

The John Watson Collection


The John Watson collection of building and decorative stones

With my primary objective of having a good look at the fossil collections in the Sedgwick Museum completed, I had a brief look at another of the museum’s unique set of geological specimens – the John Watson collection of over 2500 building and decorative stones.

Pyrenean Marbles
Held in the adjoining Cambridge University Department of Earth Sciences, access to this collection requires an appointment but, on this occasion, I was given permission to take a few photos. Having worked in the specialist building restoration industry in London, where an architect’s specification typically requires that all materials used for repairs shall “match the existing”, collections such as these are invaluable for a geologist such as myself.

Although my time in Cambridge with the Heart of England summer school was running out, I bought a copy of the Cambridge Geological Trail - an introduction to building stone -  and took a very quick look at some of the historic buildings mentioned in this excellent booklet.

The Cambridge Geology Trail

Saturday, 29 August 2015

The Sedgwick Museum


Fossil fish at the Sedgwick Museum of Earth Sciences

During my trips to South Elmsall Quarry and Alton Towers, I had encountered Permian dolostones and Triassic conglomeratic sandstones that had been laid down in marine and fluvial environments respectively, when Britain was part of Pangaea and experienced a very hot and arid environment.

Permian and Triassic Rocks
Putting myself in the position of a Tour Guide, the level of technical language needed is actually quite high, which reinforces my previous thoughts about producing a specialist English language course for geological tour guides

As any good professional knows, it takes great time and effort to develop expertise and there are certainly no short cuts available for anyone who is not a native speaker, but who wants to be able to communicate effectively with people from all over the world.

Continuing with my ideas for Geotourism, my next day out with the Heart of England summer school was in Cambridge, a low lying city set on the Gault Clay, which has been exploited along the length of its outcrop to make good quality bricks.

Very briefly, I visited the Sedgwick Museum more than 20 years ago, when attending a conference held in the Department of Earth Sciences at Cambridge University – to discuss the merits of the collections of building stones that are held by various institutions.


The Jurassic Sea

I really liked its old fashioned displays and, this time, I was able to spend an hour taking photos of some of the specimens that make this place such an important place in the development of the geological sciences. Row upon row of traditional glass cabinets are crammed full of fantastic specimens - something  to spark an interest in palaeontology or for serious research.



As a professional geologist, I am more interested in petrology than palaeontology, but you can't fail to be impressed by the wide variety of fossils - and some spectacular minerals - that can be seen here; at least two groups of teenaged summer school students, of various nationalities, and a variety of other visitors also appeared to share my views.


An artist's impression of ancient life forms


 

Tuesday, 18 August 2015

Alton Towers


A detail of Triassic sandstone

Having visited South Elmsall Quarry as part of my ongoing Geotourism project, I identified two further sites that I want to visit – Higgar Tor and Peveril Castle; however, before I could organise these, I was invited again to teach English to students with the Heart of England summer school.


A general view of the old manor house
Knowing that I would be visiting familiar places such as York, Cambridge and Alton Towers, I was able to continue with my geological work.

Of all of the thousands upon thousands of people who have visited Alton Towers, it wouldn’t surprise me if I was the only person who has ever taken the time to look at its geology.

I don’t like theme parks but, having visited it twice before, I knew that the gardens were worth further investigation.


On the geological map, the rocks at Alton Towers are shown to be of Triassic age, formed approximately 237 to 251 million years ago in an environment previously dominated by rivers –  sand and gravel deposited in channels and river terraces, with some fine silt and clay.


A view of The Gardens from the Sky Ride

From a trip on the Sky Ride, you can properly see the varied topography of the site and, once you know where to go, a relatively short walk takes you to some extensive exposures of the Bromsgrove Sandstone Formation, where the large scale cross-bedding and abundance of course pebble beds provide evidence of rapidly flowing rivers, with flash floods. 

From this point, there are also good views of the steep sided valley, where the softer sandstones and siltstones, comprising the underlying Hawksmoor Formation, have been carved away by the many natural springs and other water courses that flow here.


An exposure of Triassic sandstone at Alton Towers

Although, on this occasion, I was mainly interested in exploring the natural features at Alton Towers, the ruined manor house and The Gardens provide a good example of the use of Triassic sandstone for building. The quarry source of the building stone has not yet been investigated - a programme of restoration to The Gardens is planned so, perhaps, this is another case for the Geological Detective?


A few views of the house and gardens at Alton Towers

Saturday, 8 August 2015

South Kirkby



A geological map of the area between Treeton and South Elmsall


Having achieved my primary objective of assessing the Geotourism potential of South Elmsall Quarry, I set off on my return journey back to Treeton.


All Saints Church

On my walk to South Elmsall from Moorthorpe railway station, I had already stopped to look at various architectural details and public art and so I just walk backed down the escarpment – where I talked to a postman who was sitting on a stone wall - and took a bus back to South Kirkby, to have a quick look at All Saints Church before catching the train back to Rotherham.


A detail of All Saints Church

Unlike South Elmsall, whose development has been intimately tied to the rise and fall of the coal mining industry in Yorkshire, the history of South Kirkby goes back much further and, like in so many villages, the old church provides an excellent opportunity to look at the local building stone.

 
The tower at All Saints Church

South Kirkby is set on sandstone, which is described by the British Geological Survey as being part of the Pennine Upper Coal Measures Formation, but All Saints Church is essentially built from Permian limestone. The various colours and textures of the stones, together with their weathering characteristics, show a very interesting history of construction, rebuilding and restoration – both geologists and standing buildings archaeologists would appreciate this place. 


A sculpture in limestone
 
Walking around the village, the topography makes you stretch your legs and there are many other interesting geology related things to see, including a glacial erratic from the English Lake District...


A glacial erratic



Tuesday, 4 August 2015

A Trip to South Elmsall Quarry - Part II


The SSSI at South Elmsall Quarry

South Elmsall Quarry is of national importance because it provides an unusually complete section through a patch-reef in the Wetherby Member of the Cycle EZ1 Cadeby Formation and the report for the Geological Conservation Review is pitched at geologists with a high level of knowledge of the Permian rocks in England.

The South Elmsall Quarry Site of Special Scientific Interest

Arriving at the site, there is a layby that will accommodate a few cars but the display board, which introduces you to the geology, is somewhat obscured by the surrounding vegetation and has been damaged by high power weapons – perhaps indicating that not everyone is interested in conserving their national heritage assets.

Stromatolites

I had previously seen images on Google that showed extensive areas of managed green space but, before I could get to see the rock face, I had to wade through the various plants that were growing there in the middle of June; although the paths weren’t totally overgrown, I did graze my boots on a few stones that I couldn’t see, whilst exploring this site.

A general view of South Elmsall Quarry

In South Yorkshire, similar reefs form irregular sack like masses that strongly contrast with the surrounding well bedded limestone and, at most sites that I have seen, it is possible to see some of the palaeontology and petrology in quite fine detail but, at South Elmsall Quarry, these have largely been obscured by diagenetic processes.

A detail of the stromatolites at South Elmsall Quarry

Although I can think of better locations at which to demonstrate the features of bryozoan reefs, close up, the panoramic views of the stromatolites make this place quite spectacular and it would definitely be on the list of places to visit on a field study tour...

Saturday, 1 August 2015

A Trip to South Elmsall Quarry - Part I


An iron rich Carboniferous sandstone

I have known about South Elmsall Quarry for many years, through my Geoconservation work in South Yorkshire but, being set in a relatively remote location, it is not easy to get to without a car; not to be deterred, I set off to find this place - using the bus, the train and my own two legs. 


Halfway up the hill

On Google Map, the walk from Moorthorpe railway station to South Elmsall Quarry looks about 2.5 km. After getting off the train and walking along relatively flat land to the centre of South Elmsall, and crossing The Beck and the railway line over a continuously spanned bridge, there is a  moderately steep escarpment.


A view up the escarpment

I have crossed the unconformable boundary between Carboniferous and Permian strata very many times, whilst exploring the geology and associated ancient monuments along the length of the Magnesian Limestone escarpment; however, on this occasion, the June sunshine was strong enough to make me wilt slightly, when I thought about the walk ahead of me.


The geology around Moorthorpe and South Elmsall

Once I had started off, I soon came across an outcrop of sandstone – halfway up the hill – that caught my interest. From the online British Geological Survey map, I have since learned that this is just noted as being one of the discontinuous sandstones that form minor topographic features and are generically described as being part of the Pennine Upper Coal Measures Formation. In common with many Carboniferous sandstones that can be found all over the north of England, they exhibit cross-bedding – the product of strongly flowing rivers – and are rich in iron oxides.


Ferruginous sandstone

Moving on up the escarpment, the unconformity between the Carboniferous and Permian can be inferred by the appearance of an old quarry face that now forms part of a private housing development. A quick look at this section of the Cadeby Formation revealed a succession of relatively thin beds, with the lower section of the exposure being distinctly orange in colour and containing a high proportion of sand, which is typical of the region.


A detail of the Cadeby Formation

Walking further up to the brow of the hill, I made a mental note to myself that it is always essential to bring food and drink on a field trip, when having to take advantage of the local shop that is conveniently placed there. With some Lucozade to fill me with energy, I finally arrived at South Elmsall Quarry.



A road cutting