Dark dune spot

Imagine you are playing in the sand at the beach and you notice a spot that is darker than the rest of the sand dunes. This is called a dark dune spot. It happens because the sand in that spot is made up of different materials than the sand around it.

Sometimes, the different materials can be minerals like magnetite or ilmenite, which are dark-colored. These minerals can be found in the sand and can create a darker patch.

Other times, the dark spot can be caused by something living like a type of bacteria or fungi. These microorganisms can leave behind dark pigments that can color the sand.

Either way, dark dune spots are just areas with different materials or living things than the surrounding sand dunes, making it appear darker.