Educache
Task difficulty: 2.5 out of 5.0
Terrain difficulty: 1.5 out of 5.0
Statystyka skrzynki
Roborough Stone      OK00E3

 Item of geological and historical interest on Roborough Down.

hidden by  hobo and miss

N 50° 27.993' W 04° 06.077' (WGS84)

 Coordinates in other systems
 Location: United Kingdom > Devon
 Cache type: Educache
 Size: No container
 Status: Ready for search
 Date hidden: 07 February 2010
 Date created: 07 February 2010
 Last modified: 08 February 2010
 Waypoint: OK00E3

 



{{found}} 3 x found
{{not_found}} 0 x not found
{{comment}} 0 comments
0 cachenotes
history of visit
1 watchers
464 visitors
1 x rated
Rated as: N/A

Map
Available maps: Opencaching.org.uk
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Cache attributes

Around the clock All year round Access Winter safe Kids 

Please read the Opencaching attributes description article.

Description   EN  

Many of the churches in the West Country were rebuilt from AD 1250 onwards. Previously churches were probably wood or very primitive stone structures. Saxon and Norman stone work was usually solid and simple, robust but not as elegant as the fashions of the thirteenth century dictated. The cathedrals of the period set the trends - delicate windows and decorated doorways. As far as possible parishes, or at least their major benefactors, wished to emulate them.

There was a plentiful supply of granite (moorstone) which was hard, strong and very resistant to weathering. It could be used to build sound churches and towers which would last almost for ever. It was however almost impossible to work finely. It could not be used to make fine window tracery and decorative carvings.

On Roborough Down they found the answer!

The granites of Dartmoor were forced up from below through the rocks of the Devonian and Carboniferous periods about 290 million years ago. They did not break the surface and solidified while still underground. Granite consists mainly of quartz, mica and feldspar. The quality and colour of granite varies with the proportions of quartz, mica and feldspar, the rate of cooling and the amount and type of the absorbed materials. A dyke of rock of exactly the right combination of all these elements occurred on Roborough Down. This rock is called felsite. It is a sort of granite but it has less quartz and more feldspar than the average granite. It has the rare qualities of being easily won from the ground, very resistant to weathering and could be carved into ornate shapes.

Stone was recovered from a row of small quarries and pits on Roborough Down. Our ‘Bring Your Own Picnic’ last June was held in the most easterly of these. The row runs in a westerly direction and there is a further outcrop near Bere Ferrers. The stone has been used in the churches at Tamerton Foliot, Bickleigh, Shaugh Prior, Meavy, Sheepstor, Walkhampton and Buckland Monachorum. It was also used in Buckland Abbey and many of the better houses in the area.

There are no information boards on the site so you must search elsewhere if you need further information.

To ‘find’ this cache, visit the following places:-

a. Go to N 50° 27.993 W 004° 06.077. You will find that you are in a trough like depression, running across Roborough Down. This is the felsite quarry and after rain it is often flooded.
Photograph yourself, one of your team or your GPS with the quarry/pit in the background.
Estimate the volume of the large stone, at the location, in cubic inches.

Roborough Down is open access land. We all have the right to use and visit all parts of it without seeking anybody’s permission or approval.

b. Go to N 50° 25.635 W 004° 09.190. You will find yourself by Tamerton Foliot Church. The main structure is limestone from Plymouth but the window tracery is Roborough stone. When each of the side aisles was added to the church the old Roborough stone windows were re-used in the new walls. While you are there, notice the variations of colour of the stone caused by impurities.
Count the number of glass areas there are in the Eastern window on the South side of the church.

A footpath leads through this churchyard, past the windows concerned. This is public access and there is no need for you to leave the path or enter the church for the purposes of this cache.

c. Go to N 50° 29.445 W 004° 01.827. You will find St Leonards Well at the side of the road on the outside of the churchyard wall. You do not need to enter the churchyard. The cover of the well is built of rough hewn granite blocks but the front is felsite. The felsite front looks as though it was once part of a large window and this is an example of good stone being reused.
Work out why the two types of stone have been used.

For the purposes of this cache you do not need to leave the public road.

When recording your find please post a photograph of yourself, one of your team or your GPS with the quarry/pit in the background.

Also, please e-mail us your answers to the following questions:-

a. What properties of felsite endeared it to medieval church builders?
b. How does its composition differ from normal granite?
c. What lies between the outcrops on Roborough Down and Bere Alston?
d. What was the volume, in cubic inches, of the large stone at the first location?
e. How many glass areas were there in the window at Tamerton Foliot?
f. Why and where were the two types of stone used for the well cover at Sheepstor?

 Utilities

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Logentries    {{found}} 3x {{not_found}} 0x {{comment}} 0x      New log entry

	03 May 2010 sonatellas Found it

Found whilst out and about on the moors. Lovely day out TFTC

	21 April 2010 windrush cache hunter Found it

Took my time over this one, having visited the church, (too soon,) and the well, I finally got to the quarry today. Like Spannerman I didn't realise these indentation across the moor were small quarries, the stone must have been barely covered to leave such little trace of the extraction process.Thanks for an interesting and informative cache. Need to find out how to resize the photo now!
Pictures connected with this log entry:
Roborough stone 2
Roborough stone 2

	09 February 2010 Spannerman Found it

Well that was very interesting! I always thought the working on Roborough Down were from Tin Miners so that was something learnt today. The water was frozen over this morning and it was very cold at the quarry so I only hung around long enough to measure the stone before heading out to visit the Churches at Tamerton and Sheeps Tor. The picture of my GPSr and quarry was taken with my phone, (our main camera was working elsewhere today), so it isn't brilliant.

 

Photobucket

After visiting the St Leonards Well I went inside the church for another look round where it was noticably warmer than outside.  Back now to Tamerton for the final answer and a look around this church before heading home to do some more sums.

Thanks for your first Opencache and an interesting local lesson.  Laughing