Devil's Bridge is a place of much lore and history. The bridge crosses the River Lune, it's 3 arches harking back to Medieval times. The Devil has rumoured to have had dealings here, with the fabled story of the Old woman and her dealings with the Devil.
It is a busy place, though the bulk of folk stay up by the bridge. This EarthCache takes us to the limestone rocks which are upstream from the bridge.
🚨If the river is running high, or in spate DO NOT ATTEMPT THE EARTHCACHE.🚨
🚨 The limestone can be slippy when wet. 🚨
🚨You may get wet feet🚨
THE TERRAIN RATING REFLECTS THAT YOU MAY GET WET FEET, AND ALSO THE INCLINED NATURE OF THAT LOCATION.
This is a two stage EarthCache, though the stages are close together. The below photographs show where to look.
STAGE ONE.
STAGE TWO.
🤔 The geology of the location.
The River Lune runs under the bridge, with its origins high in the Howgills. It drains a vast area, with a lot of geology, and in places that geology can be seen in clear view. This is one of those locations. You cannot help but notice the mass of tilted rocks which lie under and around the area of the bridge. This is limestone, part of the Urswick Formation Limestone, which was deposited during the Asbian Substage. This geological period was part of the Visean Stsge of the Carboniferous Period. It is between 337 and 330.9 million years old. You will have noticed that the rocks are tilted at an angle. This is due to the Variscan Orogeny, which was a geological mountain building event, caused by the collision between two ancient continents, known as Euramerica and Gondwana, which then formed a supercontinent called Pangaea.
🤔 What are we here to look at?
We are here to look at veins, but not the type in your body. At Stage One, is you look at the face of the tilted rock, you will notice a line running down it. That is a vein.
🤔 What causes the veins to form?
The veins you see at both stages, are the result of hydrothermal action. During the Variscan Orogeny, deep in the planet, magmatic action produced heat and pressure. Magmatic, relates to anything to do with magma, which is hot molten rock deep within the Earth. This caused a hot mineral rich solution to circulate through the rock, exploiting weaknesses such as cracks. As the mineral rich solution cooled, it then formed crystals of minerals in the form of veins.
🤔 Growth Texture of Veins.
It is possible to describe the appearance of veins by how the crystals appear within the veins.
➡️ Anhedral and Euhedral.
Euhedral crystals, are well defined, this indicates that they were able to grow with no obstruction.
Anhedral crystals, are not well defined, they can have irregular shapes. They often form in a enclosed environment, where crystal growth is limited.
➡️ Growth Textures.
These are how the crystals are arranged, basically how they have grown in the veins.
COMB APPEARANCE.
MOSS APPEARANCE.
COCKADE APPEARANCE.
COLLOFORM APPEARANCE.
CRUSTIFORM APPEARANCE.
BLOCKY APPEARANCE.
📝This being an EarthCache, in order to log it, I ask that you complete the above tasks. Please send the answers to me, and do not include them in your log. You can send them to me by using the message facility or email, both of which can be found by looking at my profile.
STAGE ONE.
1. Please describe the vein, in terms of colour, crystal size, and any specific features.
2. Would you describe it as Anhedral or Euhedral?
STAGE TWO.
1. Please describe this vein in terms of appearance, size and colours.
2.What is the growth texture?