Introduction:
The listed coordinates will bring you to the "Narragansett Rune Stone." You will learn more about the geology of this stone and become more confident with identifying rocks of this type. This is an earthcache and therefore there is nothing PHYSICAL placed here. You must answer the below questions to gain credit for the find. To read more about earthcaches, please visit https://www.geosociety.org/GSA/GSA/fieldexp/EarthCache/home.aspx.
Geology Lesson:
The stone in question is a metasandstone. You may have heard of the rock type sandstone, which is what this rock started out as. Sandstone consists of sedimentary layers of sand and minerals all accumulated and cemented together in sheets. Sandstone's color is usually earth tone colors, brown, pinks, gray, sometimes red and purple. Sedimentary rocks can be found both in desert settings or near sources of water. They are very porous and when water gets in them and freezes, it can crack the rocks easily.
Metamorphic rocks are the result of heat and pressure applied to a rock. Due to the heat and pressure, this can cause the sandstone minerals to align in bands. After undergoing heat and pressure, this once sedimentary rock became a metasandstone. Metasandstone is a metamorphic rock that still resembles sandstone, but shows signs of alteration from heat and pressure. The word metamorphic means to change form. The stone can become harder and minerals can look different than they were before metamorphism.
In the diagram above, a sedimentary rock can undergo heat and pressure and turn into a metamorphic rock. There are other rock cycles as well but this earthcache won't get into those.
Questions (to receive credit please email or message me the below answers to these questions):
1. How large is this metasandstone boulder? Length x Width x Thickness?
2. Using the photo above, what type of sedimentary rock does this boulder most closely resemble? Explain your reasoning.
3. How do you know this is a metasandstone rock? What characteristics of this boulder make you think so?
4. There is a small boulder chained to one of the four structure posts. Is this a metasandstone? Why or why not?
5. Upload a photo of yourself, or your GPS, without revealing any spoilers!
Sources:
https://www.gsa.gov/real-estate/historic-preservation/historic-preservation-policy-tools/preservation-tools-resources/technical-procedures/sandstone-characteristics-uses-and-problems
https://www.sciencefacts.net/sedimentary-rocks.html
https://volcano.oregonstate.edu/metamorphic-rocks-lesson-14