This EarthCache is on the way to or from the station. Now, unlike many other towns and villages, the station is actually quite a way out of the village. It is the same with Dent and Clapham.
Here there is a handy seat to stop and have a rest. There are three stones here, we are concerned with the upright one, nearer to Giggleswick centre. You may ask what we are here to look at, we'll we are here to look at sandstone, and to decide which type.
🤔 What is sandstone?
Sandstone is a sedimentary rock, formed by sediment which has been laid down. In the case of sandstone, the sediment is sand and gravel.
➡️ How does it form?
The formation of sandstone involves two principal stages:
🔸️Initially a layer or layers of sand accumulate as the result of sedimentation, either from water (as in a stream, lake, or sea) or from air (as in a desert). Typically, sedimentation occurs by the sand settling out from suspension; i.e., ceasing to be rolled or bounced along the bottom of a body of water or ground surface (e.g., in a desert).
In the case of this location, the sandstones were deposited in a river delta environment.
🔸️Finally, once it has accumulated, the sand becomes sandstone when it is compacted by pressure of overlying deposits and cemented by the precipitation of minerals within the pore spaces between sand grains.
The most common cementing materials are silica and calcium carbonate, which are often derived either from dissolution or from alteration of the sand after it was buried. Colours will usually be tan or yellow (from a blend of the clear quartz with the dark amber feldspar content of the sand). A predominant additional colourant is iron oxide, which imparts reddish tints ranging from pink to dark red, with additional manganese imparting a purplish hue.
🤔 Is all sandstone alike?
The answer is no, like humans they all vary, there are four main classifications of sandstones, which are graywackes, lithic sandstone, arkosic sandstones, and orthoquartzites.
➡️ Greywackes.
These are a form of sandstone, which are known for their hardness. They tend to be dark in colour. There are greywackes in the North Craven area, and they are quarried near Ingleton. Greywackes can originate from sediment deposited in deep marine environments.
➡️ Lithic Sandstones.
These are types of sandstone, that contain a significant proportion of rock fragments, these are known as lithic fragments, which are basically bits of other types of rocks.
➡️ Arkosic Sandstones.
These are sandstones which have a high proportion of the mineral feldspar. They can be coarse grained, and have a pink to grey colour. Often the sediment they are formed of, was originally granite, anothet type of rock.
➡️ Orthoquartzites.
These are sandstones which have a high proportion of the mineral quartz. It often has a smooth and light grey appearance. These type of sandstones are also known as Quartzitic.
📝 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. Please define what type of sandstone there is here?
2. What is the rationale for your answer?
3. Please have your photograph taken, or that of your device sat on the seat.