This EarthCache is along the A830, which used to be known as the Road to the Isles. You will have to park in the nearby parking and then walk to the EarthCache location. DO NOT STOP ON THE ROAD.
You are here to look at an exposure of rock. The geology of the area is made up of metamorphised sandstones, more specifically psamite and pelite. Metamorphism is where heat and pressure alter the structure of a rock. Sandstone is a sedimentary rock, meaning that it was originally laid down as sediment, which then over time formed layers of rock. These layers were originally horizontal. Then , the sandstone was subjected to immense heat and pressure, which altered its structure, and in turn it was transformed into what we now know as psammites. You, would perhaps think that would be the end of the story, but tectonic forces moved the originally horizontal layers , into now near vertical layers, which you can see in front of you.
There was however another change to the rock you can see. A vein cut through the rock. A vein is an intrusion of originally mineral rich hot fluid into the rock, which when cooled formed crystals, in the form of a linear structure. Though veins are not always linear, they can be a variety of shapes. At times, veins also exploited weaknesses in rocks, such as cracks, and followed their route, as they were the route of less resistance. We are here to look at that vein.
This being an EarthCache, in order to log it, I ask that you answer some questions. Please send them 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.
1. How wide is the vein?
2. Please describe the structure of the vein, does it have large crystals, how does it feel?
3. Please describe the shape of the vein.
4. Please describe how the vein was formed.