What's underneath sunset beach? If you go up to the shore, dig up some sand, and scoop some up, you may notice that the sand is black underneath, if you continue to read this, you'll find out why.
Heavy minerals
The sand under the tan sand near the water is black mainly because of heavy minerals, such as Ilmenite, Magnetite, and Garnet. These minerals are more dense than other minerals, such as quartz. When the sand meets with the ocean, the more dense minerals are more resistant to erosion while less dense minerals will wash away or rest as a thin layer at the top. For example, if you get some rocks, and dry sand, and put them on a table, then try to blow it away, the sand blows away and the rocks stay, just like the different density's of sand and minerals.
Ilmenite and Magnetite
These are heavy minerals that are rich in titanium and are common at Florida's coast lines and beaches and are known to impart the dark color of the sand.
Garnet
This red and/or purple colored mineral can also contribute to the dark color of the sand underneath.
Fossil fragments
Black and dark brown fossil fragments, often mixed with the quartz sand, can also contribute to the dark color of the sand
Logging tasks
To claim this earth cache, do the following and answer the questions.
1, with one hand (you can use both if someone will take your picture) scoop some sand near the water line, take a picture of it and post it in your log.
2, does the black sand feel different from the tan sand?
3, does the black sand smell different?
4. If you toss some black sand in a puddle, does it sink to the bottom quickly, or does it make a cloud in the water?
To submit answers, message me the answers by using in app messaging. Thanks!
Sources
1. https://www.southernshores-nc.gov/community/page/beach-nourishment-why-sand-newly-dredged-beach-black
2. https://en.wikipedia.org/wiki/Black_sand
3. https://oceanservice.noaa.gov/facts/sand.html#:~:text=Black%20sand%20comes%20from%20eroded,on%20beaches%20near%20volcanic%20activity.
4. https://www.visitflorida.com/travel-ideas/articles/florida-white-orange-dark-sand-beaches/