This EarthCache takes you to the war memorial in Horton in Ribblesdale. Please be respectful to the location.
The geology of the area is very varied, with the oldest rocks being from the Silurian and Ordovician Periods, when there was an ancient ocean where sediment was deposited. Then there the Carboniferous Period rocks such as limestone and sandstone. Though this war memorial is of a different type of rock, one known as granite.
🤔 There are different types of rock.
🪨 Sedimentary.
Examples are sandstone, mudstone or limestone. In these cases sediment has been laid down to form layers which have piled up above another to form a rock. You could think of sedimentary rocks as layers in a cake.
🪨 Metamorphic.
These are rocks which have been altered by heat and/or pressure, for example marble was once limestone which has been changed by heat and pressure.
🪨 Igneous rocks.
Igneous rock is formed through the cooling and solidification of magma or lava. Igneous rock forms by crystallisation either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.
The war memorial is made from granite, which is an igneous rock. Granite is not local to this area, and can commonly be found in South West Scotland and also in Grampian where it has been quarried in the past. It is a very hard rock, which does not break down easily when exposed to wind, rain and hot / cold temperatures. It is composed of minerals which can be seen easily using the naked eye.
◻️ Quartz. This is a clear or greyish mineral, and is the most common mineral found on the surface of the earth.
◻️ Mica. This is a black or sivery mineral, which looklike flakes.
◻️Feldspar. This comes in a range of colours. Pink or white feldspar is known as as orthoclase, whilst grey is known as plagioclase. The pink colour, comes from K-Spar, which is also known as potassium feldspar.
🤔 Feldspar.
Feldspar is often the component in granite that influences its colour, as feldspar can be white, pink and red. Its crystals, as shown in the above image, can be blocky, elongated or rectangular. Looking at the feldspar crystals can help understand about the activity of magma during the formation of granite. Sometimes feldspar crystals can be aligned together in the same direction, this gives an indication as to the direction of magma flow. An unaligned collection of feldspar crystals , can indicate that feldspar crystal formation started after the magma had cooled sufficiently that it started to become rigid.
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.
1. What colour of feldspar has affected this granite war memorial?
2. Is there any evidence of feldspar crystal alignment?
3. Considering your answer to question 2, what state was the magma in when these feldspar crystals were formed? Was it flowing, or becoming more rigid?
If anybody would like to expand to this series please do, I would just ask that you could let Just-Us-Two know first at justustwo1013@gmail.com so they can keep track of the memorial numbers and names to avoid any duplication.