Stonesfield Slate EarthCache
-
Difficulty:
-
-
Terrain:
-
Size: 
(not chosen)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
The Cotswolds Natural Area overlies a band of limestone stretching from Somerset to Warwickshire. These Jurassic Limestones are internationally famous, as many are rich in fossils, and the rock stratigraphy is of particular importance.
Characerteristics include:
- Limestone scarp and outliers illustrating escarpments slowly worn back.
- Mass movement of limestone over underlying clay, Fullers Earth or sands give rise to landslip features along scarp, valleys and outliers.
- Water sinks into the limestone emerging as spring lines along scarp and river valleys.
- Cotswold streams and rivers emerge and flow through dissected valleys of the dip slope.
- Limestone geology limits surface waters and draws historic settlement pattern to springlines.
- Lower Jurassic rocks exposed in the north and the glacial drift give rise to more hummocky landform.
- Lias clay rocks form the floor of the Vale of Morton giving rise to a distinctive subarea.
Stonesfield derives from the name Stunsfeld used at the time of the Domesday Book. Stunsfeld means "fools field" because of the stony nature of the soil in the area.
In and around the village of Stonesfield, part of the Middle Jurassic Great Oolite succession has been worked for the production of roofing slates, giving rise to the Stonesfield Slates. This fine-grained rock type is very localised and was probably deposited in a shallow marine environment. The mines are no longer worked, but during production they yielded abundant remains of fossil plesiosaurs, marine crocodiles, dinosaurs, pterosaurs, turtles and plants. These occur as well preserved teeth, limb bones and vertebrae. The Stonesfield Slate yielded in 1812 the first known pre-Tertiary mammals and in 1815 several bones belonging to a ‘giant lizard’. These bones were studied by the great zoologist and geologist, William Buckland's who in 1824 formally named and described them as Megalosaurus (Gigantic Lizard) – this was the first dinosaur to be scientifically described.
From the size of the bones, it is estimated that the animal had been forty foot in length and twelve feet high.
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. The result is a foliated rock in which the foliation may not correspond to the original sedimentary layering.
The Stonesfield slate consists of two beds of yellowish or greyish oolitic limestone, each about two feet thick and seperated by a bed of loose calcareous sandstone about the same thickness.
At the cache page location you are at Stonefield Ford at old open quaries of Stonefield Slate. What are you thoughts as to why the slate is here?
What do you notice about the course of the riverbed? Why does the river flow here rather than taking a short cut south? What could happen in the future?
E-mail the answers through my account.
FYI:
Here aresome nearby SSSI sites, but you may be surprised toknow that you cannot see anything if you visited the sites:
SP379173 = N 51° 51.181 W 001° 27.069
SP392172 = N 51° 51.121 W 001° 25.937
SP388168 = N 51° 50.907 W 001° 26.288
SP387171 = N 51° 51.069 W 001° 26.373
The most exciting way to learn about the Earth and its processes is to get into the outdoors and experience it first-hand. Visiting an Earthcache is a great outdoor activity the whole family can enjoy. An Earthcache is a special place that people can visit to learn about a unique geoscience feature or aspect of our Earth. Earthcaches include a set of educational notes and the details about where to find the location (latitude and longitude). Visitors to Earthcaches can see how our planet has been shaped by geological processes, how we manage the resources and how scientists gather evidence to learn about the Earth. To find out more click HERE.
Additional Hints
(Decrypt)
[Answer to question 1 can be found with the cache page and from your observations onsite. Answer to the second question will need additional thought and research.]