Friday, 29 July 2022

Wellington's Monument & Baslow Edge

The Eagle Stone

With the exception of my day out to further explore the Sheffield Board Schools, most of my trips during August had so far been very geological and a few days after exploring Roundhay Park, I took advantage of the regular buses that run from Sheffield to Bakewell and Castleton to further explore the Peak District National Park.
The route from Clodhall Lane Crossroads to Curbar Edge
Alighting from the TM Travel No. 218 bus at Clodhall Lane Crossroads, my plan was to walk along the public footpaths on the Chatsworth Grit from here to Wellington’s Monument and then continue to Fox House via Baslow Edge, Curbar Edge, Froggatt Edge and the Longshaw Estate. 
Within a few minutes,  I came across a Companion Stone on Eaglestone Flat, one of a set of twelve modern interpretations of the C18 guide stoops, which were erected to assist travellers across the moors. Their production involved the collaboration of various local poets and artists with landowners and were erected near to existing original guide stoops in 2010. 
A Companion Stone at Eaglestone Flat
At the time of my walk, I didn’t know what this stone was and I didn’t make the connection with an original guide stoop on the Chesterfield Road, which is located by the track and comprises a large inscribed post made from the local gritstone. 
The Chesterfield Road guide stoop
The path runs alongside the edge of a steep woodland covered slope to the south, which falls steeply to the valley that separates it from Gardom’s Edge and down which runs the Sheffield Road to the low lying area around the River Derwent at Baslow. At one place, it is interrupted by a stream flowing from the moorland plateau, which has cut down into the boulder strewn head that covers the slopes. 
A deposit of head exposed by a stream
To the north there is an area of heather and bracken moorland, which forms a rather monotonous landscape. Boulders of gritstone occasionally project from the vegetation and the skyline is often in the form of benches produced by the weathering of the Rough Rock and associated strata. 
A large boulder of Chatsworth Grit

I next came to Wellington’s Monument, a large gritstone cross set upon an outcrop of Chatsworth Grit, which was erected in 1885 by a Dr. Wrench, a local resident who thought it was appropriate to build a monument to the Duke of Wellington, which would complement Nelson’s Monument on Gardom’s Edge. 
Wellington's Monument
Continuing along the path to the edge of the escarpment, where I was expecting to see the typical coarse grained Chatsworth Grit, with its seams of fingernail sized pebbles, however, I was surprised to see a series of flaggy beds exposed in the path. 
Flaggy beds in the Chatsworth Grit

The Chatsworth Grit actually comprises two leaves of sandstone separated by up to 65 metres of shale, in which are developed beds of sandstone. The thin planar bedded sandstone that I saw forms the lower part of the upper leaf and has soft partings, with the sample I collected being pale brown in colour and fine grained. 
A specimen of flaggy Chatsworth Grit (21 mm diameter coin)
From this vantage point, there are great views of Chatsworth Park, where the River Derwent has cut through the strata that lie beneath the Chatsworth Grit, including the Ashover Grit, to leave a very pronounced valley. 
A view towards Chatsworth Park

I then returned to the main path towards Curbar Edge, where the Eagle Stone - an isolated tor of Chatsworth Grit - forms a very distinctive landmark that is well known to the very many walkers who have explored Baslow Edge over the years. 
The Eagle Stone
The public footpath doesn’t run near to the gritstone edge and I therefore quickly walked along it, taking care to avoid the ruts that have developed in places, until I came to the start of Curbar Edge, which I last visited with the Sheffield U3A Geology Group on a very wet and windy day back in November 2015.
A view of Curbar Edge

Roundhay Park - A Walk Back in Time

Fossil bivalves

My exploration of the Jurassic Trail in Leeds, in the middle of August 2021, was followed five days later by another trip to Leeds – this time with the Sheffield U3A Geology Group, to explore the geology around Roundhay Park. 
A Walk Back in Time
Back in 2015, I had a good walk around Roundhay Park during a day out to Leeds and noted some interesting historic buildings, follies and a few geological features along The Gorge, but I was unable to obtain a copy of Roundhay Park – A Walk Back in Time, produced by Bill Fraser of the Leeds Geological Association. 
For most of our trips, the Group uses various books, guides and leaflets that members have collected over the years - to plan the walks - and the Group field trip leader of the day would lead us around using one of these; however, on this occasion it was arranged for Bill himself to lead more than twenty of us around Roundhay Park – starting at The Mansion House. 
Gathering at the Mansion House

Taking a path around the Upper Lake, which I had not previously explored, we saw various exposures of the thinly bedded Elland Flags from the Lower Coal Measures exposed in the streambed and then made our way to The Castle - a sham ruined castle gatehouse built for Thomas Nicholson, which is built out of large glaciofluvial cobbles from the nearby Quaternary Harrogate Till Formation, with gritstone for the dressings. 
At The Castle
Continuing to the top of The Gorge, we then followed the banks of the brook and stopped at numbered waymarkers, which correspond to the places of interest noted in A Walk Back in Time. Much to our great surprise, Bill then proceeded to unpack a large number of rocks and fossils that he had collected over the years from his rucksack, which we passed around the Group. 
A goniatite

The rocks that we looked at in The Gorge comprise sandstones, siltstones, mudstones and shales that are found beneath the Rough Rock, which is the uppermost named formation in the Millstone Grit Group but in reality are not much different to the sequences of rocks being laid down as the Lower Coal Measures strata.
An exposure of shale in the streambank

I didn’t take my Estwing hammer with me on this occasion and I gratefully received a few specimens of West Yorkshire sandstones and shales, which have been added to my rapidly growing collection of the rocks of Yorkshire and Derbyshire. 
Various samples of rock from The Gorge
Our next stop was at Scouts Quarry, where we inspected an exposure of the Rough Rock, which contains fingernail sized pebbles that were once rolled along the bottom of a massive river channel, in which dunes of coarse sand were also being pushed downstream. 
Differential weathering of softer beds in the Rough Rock
Of particular interest here is a soft sandy bed that has differentially weathered away to an arm’s length, which is a not feature of any of the exposures of coarse gritstone that I have seen around Derbyshire or Sheffield. 
A Lepidodendron fossil

Here, Bill retrieved yet another specimen from his rucksack, this time a piece of medium grained gritstone that contains a Lepidodendron fossil, which is more commonly found in the overlying Lower Coal Measures strata. 
An exposure of the Elland Flags

Continuing down the path along the stream, where we stopped at further examples of the Rough Rock, we then crossed the Roundhay Park Fault and eventually came to Waterloo Lake, where small exposures of the Elland Flags exhibit worm burrows on the bedding planes. 
Worm burrows exposed on a bedding plane

We finished our walk at the end of a surprisingly long day, by walking round the south end of the lake and heading back up to The Mansion, which I was told is built using a more massive variety of the Elland Flags - best known for its thinly bedded paving and roofing stone. 

The east elevation of The Mansion

Thursday, 28 July 2022

Dinosaurs in Leeds - Part 2


Continuing with the Jurassic Trail 2 in Leeds, after spending 30 minutes at the Church of St. John the Evangelist, the next dinosaur that I encountered was Diplodocus on Briggate. This long necked herbivore lived in the Late Jurassic 155-145 million years ago (mya) and was up to 26 metres long. 

At this point, having seen half of the dinosaurs on the trail, I headed off to get some lunch at Khao Gaeng Thai in Kirkgate Market, a place that I discovered in January 2019, when planning a Sheffield U3A Geology Group field trip to Leeds and have eaten at several times since. 
My dinner at Khao Gaeng Thai

Feeling better for having had yet another tasty Thai meal, the next venue on my list was the St. John’s Centre, Here, I encountered Stygimoloch, a pachycephalosaur from the Late Cretaceous (70-65 mya), which probably fed off horsetails, gingkos, cycads and club mosses. 

Immediately next to this was Pachycephalosaurus, meaning ‘thick headed lizard’, another herbivore from the Late Cretaceous (75-65 mya) that is believed to have fed primarily off plants, fruits and seeds. 

Moving on to the Merrion Centre, the next dinosaur that I found was the Late Jurassic (155-145 mya) Stegosaurus, a herbivore that I was familiar with during my childhood interest in dinosaurs, but which would have been beyond my abilities to reproduce it in clay – as I had done with Triceratops, which was the next on the trail. 
Triceratops, which was surprisingly fitted with a saddle upon which the children sit would sit for a ride, lived in the Late Cretaceous (68-66 mya). This was one of my favourites as a child and it gained in popularity when appearing in the original Jurassic Park. 

Leaving the Merrion Centre, I headed down to The Headrow to see if there was anything worth seeing at the Leeds Art Gallery or the Henry Moore Institute, but I got no further than the magnificent Britain From The Air exhibition. 

A selection of images at Britain From The Air

After half an hour spent admiring these aerial photos, which included views of mountainous landscapes, castles and sprawling country houses, I resumed my search for dinosaurs at The Light shopping centre, where I found the Late Jurassic (156-144 mya) carnivorous Allosaurus. 

Continuing my walk to The Core, the Early Jurassic (190 mya) Dilophosaurus is another of the dinosaurs featured in Jurassic Park, where it is depicted with a frill, which is actually thought not to have existed by palaeontologists. Its bright colours also provided a timely reminder that the colouration of dinosaurs is still largely a matter of speculation. 

To see the final dinosaur on the trail, I headed off back toward Leeds railway station to Trinity Kitchen, where there were a couple of Late Cretaceous (74-70 mya) Velociraptors, which appeared in the scariest moments of Jurassic Park.

Tuesday, 26 July 2022

The Church of St. John the Evangelist

A sundial on the porch

When planning my day out to see the dinosaurs on the Jurassic Trail 2 in Leeds, I wanted to take advantage of the limited opening hours of the disused Church of St. John the Evangelist, which is now maintained by the Churches Conservation Trust. 
A general view of the south elevation
Seeing it for the first time during a previous visit to Leeds, I assumed that it was a C15 church, based on the Perpendicular Gothic style throughout the exterior, but was surprised to discover that it was in fact completed in 1634, with alterations to the tower from 1830 to 1838 and a major restoration by Richard Norman Shaw, which was completed in 1868. 
A general view of the north elevation
In the 1860’s, it was was originally intended that the church whould be demolished and rebuilt, as at Leeds Minster but Shaw, supported by George Gilbert Scott, was able to convince the church authorities that it could be repaired. 
Coarse pebbly gritstone used in the porch

Although originally built in stone from the Upper Carboniferous Elland Flags, which came from the mediaeval quarries of Woodhouse Moor to the north-west of the city centre, the restoration work made extensive used of coarse grained pebbly sandstone that is probably from the Rough Rock. I didn’t closely examine the masonry but I can’t say that I noticed any of the fine grained original stone.
A grotesque on the porch
I just spent enough time on the exterior to photograph its principal features and the large grave slabs that cover the churchyard and which are probably made with memorial grade stone from the Elland Flags – a very fine grained sandstone that, like the Greenmoor Rock in South yorkshire, was widely quarried for paving. 
Grave slabs in the churchyard

The interior is best known for its double nave, box pews, well exposed roof timbers and various other fittings that are very attractive, but the walls are all plastered and there is very little exposed stonework to be seen anywhere. 
The arcade

The single central arcade is built out of fine grain buff coloured sandstone from the Woodhouse Moor quarries, which is very different in character to the flaggy sandstone for which the Elland Flags are best known. 
Decoration to a capital in the arcade

The octagonal columns of the arcade have capitals that are decorated with acanthus leaves and ball ornament and various carved head and figures, some of which are playing musical instruments, are found on both sides at the springing of the arches. 
An angel playing a musical instrument
The church has a fine floor, which is laid with large squares of the grey veined ‘Sicilian’ variety of Carrara marble and a red/grey polished Devonian limestone from Belgium, which may be Rouge Royal ‘marble’ or a similar variety from central Wallonia. 
The chequer pattern marble floor

Another decorative stone used in the floor, for borders, is the polished Carboniferous limestone known as Frosterley Marble, which comes from Weardale in Co. Durham and is composed of rugose coral fossils set in a black calcareous mud matrix. Also, in one of the window ledges is what I think is Connemara Marble from Co. Galway on the west coast of Ireland, but I couldn’t get close enough to take a good look at it. 
Fosterley Marble and Connemara Marble

Friday, 22 July 2022

Dinosaurs in Leeds - Part 1

A Tyrannosaurus in Leeds Trinity shopping centre
When writing this Language of Stone Blog, I started out with the intention to publicise my various professional work as a geologist and building stone specalist, restorer of historic buildings, photographer, writer, artist and teacher of English as a foreign language – all of which have grown from a passion for stone that I have had since I first collected pebbles on the beach as a baby - and is essentially an extended, illustrated Curriculum Vitae. 
A prize for creative writing
Having spent my first two days out in August to further survey the Magnesian Limestone in Rotherham and to investigate the Sheffield Board Schools, my next day out to Leeds was for pure pleasure. This harked back to my childhood fascination for dinosaurs – which influenced books that I chose when winning writing competitions in London, ceramic Plesiosaur and Triceratops that I made at Macaulay Primary School and the occasional set of stamps that I have bought since. 
A set of dinosaur stamps

In recent years, I have been on a mailing list for events in Leeds and I was particularly interested in the Jurassic Trail 2 that was being arranged for the school summer holidays, with life sized animatronic dinosaurs being located in the principal shopping centres - an event that is being repeated this summer as the Jurassic Trail 3. 
The Leeds Dinosaur Map
Arriving on the train from Sheffield, my first encounter was with the genus Baronyx in the Leeds station ticket office, whose name means “heavy claw”. This carnivore, which actually lived in the Early Cretaceous Period 130-125 million years ago (mya), primarily ate fish, but evidence of Iguanodon teeth associated with fossil finds suggest that it was also a scavenger and would feed on other dead dinosaurs. 
Baryonx in Leeds railway station
My interest in dinosaurs soon disappeared and I can’t recall been taught anything about them as an undergraduate geologist and, for my generation and very many others since, Steven Spielberg’s magnificent Jurassic Park and its sequels brought them back to life and terrify us – even though a palaeontologist might criticise these for their depiction of mainly Cretaceous dinosaurs. 
Tyrannosaurus in Leeds Trinity shopping centre
Continuing to the Leeds Trinity shopping centre, which like nearly all of the venues hosting these dinosaurs I had never visited before, the Late Cretaceous Tyrannosaurus (68-66 mya), with its massive animated jaws, was certainly very impressive. 
Spinosaurus in the Corn Exchange
The next dinosaur to be found on the trail at the Corn Exchange was the Late Cretaceous ((95-70 mya) Spinosaurus which, based on fragmentary remains in North Africa, is estimated to be 18 metres in length and therefore the longest known carnivore. 
A description of Spinosaurus

Although I have a general interest in the discovery of new species of dinosaurs, which might be announced on the public news or general science websites that I subscribe to, I still know very little about dinosaurs and I assumed that the anatomical details were based on up to date research; however, the Yorkshiresaurus at the Kirkgate Market was a complete fabrication. 
Yorkshiresaurus in the Kirkgate Market food hall
Leaving Kirkgate Market, the Victoria Centre was the next venue on my agenda, this time to see Amargasaurus, which I have to admit I had never heard of before. This Early Cretaceous (132-127 mya) herbivore is found in Argentina and has a double row of dorsal spines, which may have had a ‘sail’ attached to them and the spines on the neck vertebrae are very long. 
Amargasaurus in the Victoria Centre
When visiting the eastern part of Leeds city centre, when preparing a field trip with the Sheffield U3A Geology Group to look at its building stones, I got to know my way around the streets quite well and it only took 35 minutes from leaving Leeds railway station before I arrived at Victoria Leeds, where I found the Late Cretaceous (90-85 mya) Pteranodons.

Pteranodons in the Victoria Leeds shopping centre