🇲🇦The Atlas Mountains, Marrakech, Casablanca and Fes are a long way from Edinburgh, though here amidst the Scotsman Steps you get the chance to stand upon and explore a bit of Morroco.
Start at the bottom of the Steps and then count up to 34 Steps, and you are here, the site of this EarthCache. If you are numerically challenged like me, you need to be on one of the landings, a brown landing.
The Scotsmans Steps have a wide variety of stones from around the world, though this one is useful for a geological lesson, indeed to be a geological detective 🕵♂️. To be a geological detective we need to take some steps in order to learn about and understand the geology.
🕵♂️The geology of the step.
The step is formed from a type of stone from Morroco, which is also described as a marble. The stone was formed when part of what is now Morroco was under a shallow tropical sea, during the Devonian Period. The Devonian Period occured 419 to 350 millions of years ago, and it was one full of marine life. Over time the shelly remains of animals and sediment built up on the sea floor, which over millenia formed layers, compacted and then stone was formed, which in this case was limestone. As limestone is formed from the remains of ancient sea creatures, it can be described as being fossilarious, which means having fossils in it.
🕵♂️Fossils.
Fossils are the preserved remains of animals, plants and also of movement, such as footprints. What happens is that an animal such as a shellfish dies, it settles to the seafloor, over time it gets covered in sediment, and as the stone forms it actually becomes part of the structure of the stone. Fossils can be a variety of shapes and sizes, such as ammonites look like coiled structures, belomonites look like spearheads, and shells look like shells.
🕵♂️Marble and Metamorphism.
When a type of stone is formed, at times this may not be the end of its geological journey. If we consider the age of a stone like we have here, there is plenty of time, indeed millions of years for further events to happen. The surface of the planet is called the crust, and rather than being one solid entity, it is indeed composed of many sections known as plates, or to be more precise Tectonic Plates. These can move very slowly, and indeed rub against each other, and also compress each other at times. This can cause immense heat and physical pressure, which when it affects a stone as limestone can cause it to actually transform, into another form. Marble is a stone that was once another type of stone. This original stone is known as a prolith. In the case of marble the prolith is marble. Now sometimes when we talk about marble, we have to be a geological detective, and actually question whether it is really marble. You see, limestone can actually be polished highly to appear like marble, and in the UK there are a few examples, such as Dent Marble and Frosterley Marble. So, how to do a bit of detective work and work out us something Marble or not. Well, the process of metamorphism alters the structure of the prolith, to such an extent that previous features such as fossils are no longer apparent.
This being an EarthCache, in order to log it, I ask that you answer the below 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. Please describe the colour of this step and are there any specific features, if so what?
2. Having read the EarthCache description would you describe this step as a true marble, yes or no?
3. What is the rationale for your answer?
4. Please have your photograph taken at either the top or bottom entrance to the Scotsman Steps, you can also include your device or an item with your Geocaching name on it.