From a distance, the sandy beach looks like a large golden beach next to the sea. However, if you take out a microscope to observe the sand, a whole new world appears. In particular, the ingredients that make up the sand beaches are also extremely rich, some of the ingredients revealed below may surprise you!
As rivers flow downstream, flowing water erodes rocks into tiny rock particles, while at the same time carrying these small pieces of rock. Along the river’s journey, the pebbles continue to erode, eventually becoming sand as the river flows into the sea.
When rivers flow into the ocean, sand deposits are deposited along the mainland. The waves continuously shift the deposited sand of the river, creating beautiful coasts.
The sand will look slightly different in different parts of the world, depending on the type of rock eroded by the river.
Brown and yellow sand is usually made up of feldspar – a mineral that contains iron oxide like quartz, giving it a golden brown color. The darker sand is due to basalt, formed from volcanic activity. This type of sand is often found in ocean crust or where volcanic activity is active, such as the Hawaiian islands.
The image below shows sand from Hawaii under a microscope. Green pebbles are a mineral called olivine, a mineral that is derived from volcanic basalt. The black spots in the picture are basalt. Hawaii has many active volcanoes, which explains why this sand is found there.
The size of sand grains is determined by the degree of weathering. Fine grains of sand mean that they have been weathered for longer periods by water.
Researching the minerals in the sand gives geologists a great deal about how soils form. For example, by studying basalt-rich sand in Hawaii, scientists can study an island’s origin and determine when and how it formed.
Interestingly, desert sand also comes from the sand near the beaches. When waves hit the coast at an inclined angle, sand at the beach stretches, extending the coastline. However, sometimes the wind blows sand onto the mainland, creating sand dunes.
Bones and shells of marine life
In fact, sand is made up of the skeletons of many invertebrates, such as clams, corals and other marine shellfish. Waves bring them ashore, where they settle. These objects erode very slowly, making it difficult to become finer sand.
There are a number of other creatures that contribute to sand around the world. For example, the foraminifera creates pink beaches in Bermuda. Holes are single-celled shellfish that live in the ocean. Some species of wormhole have a red color that gives Bermuda’s sand a pink color.
These red hole nematodes live near coral reefs in Bermuda. When they die, their red-shelled skeletons are brought ashore, where they blend with white sand to create picturesque pink sands.
Feces of fish
Sand is also made from manure. Yes, you heard right… and more specifically parrot fish droppings
Parrot fish are like cows of the sea. These colorful tropical fish spend almost 90% of their time eating corals, or rather algae that grow on them. They use their hard beak-like mouth to scrape and eat corals for their daily meals.
When the coral passes through the parrot fish’s intestines, the algae in the coral will be digested, while the calcium carbonate rocks that make up the coral remain. Because the parrot fish cannot digest calcium carbonate, it will be excreted in the form of fine powdered sand.
One large parrot fish can produce up to 450 kilograms (1,000 pounds) of calcium carbonate sand in a year. The mesmerizing white tropical beaches in Hawaii, the Maldives and the Caribbean are mainly formed from the droppings of parrot fish.
Although we cannot see it, sand also contains a rich micro-ecosystem that is important for the health of large ecosystems and various interdependent ecosystems.
Algae are very common in the sand. These algae can photosynthesize and produce a variety of molecules (don’t forget the oxygen from photosynthesis), becoming part of a healthy ecosystem. Many marine or coastal organisms depend on these algae, making them an important part of the food web.
Human waste can also form beaches. In 1949, the State of California began using what is now Glass Beach as a gathering yard for all kinds of trash, from cars and food to pots and glass. Finally, after nearly 20 years, the authorities realized that dumping there was not the best option and closed the area.
Gradually, a number of cleaning initiatives began to work on the beach. Toxic waste has been removed and biodegradable material has been degraded. The water eroded tiny pieces of glass and clay from the pots by rounding them up and giving the beach a colorful effect.
The sand isn’t just here to make sand castles or sunbathing… it opens up new ways for us to see the world – and our place in it!