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Please feel free to log your find and send your message at the same time.
This location is just off the path but you will need to clamber amongst and even on the rocks.
Sandstone
Sandstone forms over the course of centuries, as deposits of sand accumulate in rivers, lakes or on the ocean floor, and the sand blends with calcite or quarts and then undergoes compression. It can also form as an accumulation of sand moved about in deserts by storms and violent winds regularly depositing sand in the same location. As enough time goes by, the pressure pushes all of these elements together to create sandstone. Because not all sand is identical but instead comes in a variety of colours and grain textures, each formation has a unique appearance.
A lot of the structures there are carved out of sandstone because it is a durable rock with consistent structure. Sometimes instead of containing a uniform appearance, though, the weavings of colour make the rock look like they are made of marble cake or marble rye bread.
Some archaeologists have studied the formation of sandstone to determine how different layers of colour ended up in the same sandstone. The most common theory is that a mixture of various sand types split into layers as the sand accumulated centuries or even millions of years ago. A similar process takes place in avalanches as the chaos of movement ensures that no two layers contain the same type of material.
If you find sandstone here you will find it is made of thick layers which are consistent in structure and very durable but when you rub with your hand small grains will come off.
Granite is a coloured igneous rock with crystals large enough to be visible with the unaided eye. It forms from the slow crystallization of magma below Earth's surface. Granite is composed mainly of quartz and feldspar with minor amounts of mica, amphiboles, and other minerals. This mineral composition usually results in dark mineral crystals easily visible throughout the rock. Pink granite, like other granites is an intrusive igneous rock typically containing feldspar, quartz, mica & amphibole minerals. This variation contains potassium feldspar plagioclase that gives the granite a distinctive pink colour as opposed to other variants which can be white, grey, dark brown or even black.
If you find granite here you will find coloured crystals in the rock and the rock will be very hard so will not be able to rub away any of the rock with your hand.
Weathering is the breakdown of rocks at the Earth’s surface, by the action of rainwater, extremes of temperature, and biological activity. It does not involve the removal of rock material. There are three types of weathering, chemical, biological and physical,
Physical weathering occurs when rock is subjected to changes in temperature. Freeze-thaw occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart. This can happen at a microscopic level as well as in larger visible cracks, resulting in grains or even small rocks breaking away.
Erosion is the process by which soil and rock particles are worn away and moved elsewhere by wind, water or ice. Weathering and erosion acting together will break down even the hardest rocks and transport particles away from it resulting in a change in how the rock looks and feels. When rock is eroded by the same process over and over it is likely that deep valleys and fissures will be created in the rock as the weathered particles are eroded away.
So it’s a simple task, all you have to do now is answer the questions below
- Please describe the stone at this location telling me about the structure and hardness of the stone
- Please tell me the type of stone and explain your reasoning
- Please tell me about the rock surfaces and why it has several indentations in it.
Thank you for visiting the area and having a go at this simple EarthCache.
Please send answers at the same time you log your find.
Happy Caching
treboR