Article reprinted from Earth Magazine
Great views of the natural sandy beach
At night, when we walk on the beach, in the moonlight, there are shining stars left behind, and the tide rises and falls, washing every colored grain of sand on the beach. At the back of the beautiful Bikini Beach is the legendary starry beach.
Is there such a colorful beach on the vast earth?
Mysterious legend - colorful beach
The coast of the Maldives has yellow, white and blue sandy beaches. Under the brilliant sun, the water waves are gentle, and the white sand beaches along the coast are like delicate snow scenes under the hot sun; At night, on the blue sand side of Wadu Island, the stars are scattered in the sea, and the beach gathers into a blue galaxy, like the Milky Way left from the sky, strolling through it, as if you are in the vast universe; The pale pink beaches of the Bahamas, intertwined with the turquoise waters of the Atlantic Ocean, ink out the appearance of "dream paradise"; The orange sands of the Maltese Islands are like orange sodas, immersed in the beauty of nature. The beaches of the Hawaiian Islands are closest to the legendary colorful beaches. The warm red sands of Maui Island, the fiery colors of the flames bring people into the exotic space for a second; Punaruwu Beach has a pure and deep black sand beach, like a taciturn maiden, mysterious and romantic; Papakoli Beach is a fresh, light olive-green color, like spread matcha-flavored ice cream.
On the mainland's 32,000-kilometre stretch of coastline, the beaches are predominantly yellow, interspersed with black and white. Coastal residents, the happiest time to steal leisure, is to go to the beach after dinner, let the salty and fresh sea breeze, blow away the tiredness of the day; Sit on the beach and listen to the heartbeat of the tides with your loved ones. The golden beach in Qingdao, Shandong, the Gulangyu beach in Xiamen, Fujian, the silver beach in The North Sea of Guangxi, and the Yalong Bay in Sanya, Hainan, are all tourist resorts that everyone yearns for. Wuzhizhou Island and Xisha Islands in Sanya, Hainan Are Special White Sand Beaches, with delicate and soft sand that is like stepping on a cloud. The black sand beaches of Kichijin Island in Kaohsiung, Taiwan, will give people a cold and mysterious feeling.
Fuxian Lake Red Mountain Tsui
- Pink sand
The wonder of colorful beaches is not an intentional creation of nature, nor is it a day-made. How did the pale pink sands of the Bahamas, the orange sands of the Maltese Islands, and the colorful sands of the Hawaiian Islands come to be? In fact, the color of the beach is mainly affected by its constituent component, the beach sediment, which is repeatedly washed away by the waves that crash on the shore and abrades into the colored mineral sand particles on the beach.
When a large amount of red coral on the seabed is crushed into a fine powder by the seawater, it merges with the fine white sand on the shore to form a romantic pink sand beach. When the abundance of quartz minerals gathered on the beach is high, the beach appears as white as snow, or when the remains of marine life such as coral shellfish are crushed and eroded by the seawater, it can also form a white sand beach.
White sand beaches in the Maldives
In the day-to-day washing of the waves, the yellow quartz with the widest source, containing minerals such as iron, is left behind, forming the most widely distributed and common yellow sand beach. The sand on the blue sand beach is not blue, but a bioluminescent phenomenon caused by plankton on the coast at night, also known as "sea fire". The intensity of "sea fire" is also a "warning light" for judging the marine environment, and too much plankton will cause biological pollution and damage the marine ecological environment.
The Hawaiian Islands are volcanic islands and a famous volcanic activity area in the Pacific Ocean, where the volcano spews hot lava, condenses into volcanic rock, encounters icy sea water disintegration and fragmentation, volcanic rock rich in dark minerals such as iron and magnesium, which are washed away and eroded into black sand, forming a silent black sand beach. When the black magnetite is oxidized into brick-red iron oxides, forming a warm red sand beach; When the magmatic rock is rich in green peridot, the beach takes on a fresh green color. The colorful beaches of the Hawaiian Islands are not only beautiful, so they are also called "coastal placer mines".
Flying treasure - coastal placer mine
The big waves are sandy, and the sinker is gold. As an infused area of natural forces, the coast is full of treasures and hidden gold. There have been several gold rushes in history, and the origin of the name "San Francisco" also confirms the history of coastal gold panning. Placer gold is often short or granular, concentrated in the sand layer of the beach, widely distributed, large reserves, and convenient to mine.
Hand-sourced natural gold
The most abundant content in coastal placer mines is quartz minerals, which can be processed to make semiconductor chips. Considering that the amount of sand is so huge, if it is developed, the whole world can achieve "silicon freedom". The chip is made of a single crystalline silicon-based material, while the quartz in the sand is mainly silica. First of all, the silicon is extracted from the sand quartz with carbon, purified into high-purity amorphous silicon and polycrystalline silicon, and then converted into monocrystalline silicon through specific technologies before it can be used as a chip material.
Conversion of sand to monocrystalline silicon
In the sea sand, a variety of useful associated minerals such as magnetite, ilmenite, zircon, monazite and solitaire can also be sorted.
Magnetite, as the most important and common black iron ore, is mainly composed of ferric tetroxide, which has a metallic luster or semi-metallic luster. Finely fragmented magnetite particles are enriched by the sea to form a black sand beach. When magnetite is oxidized into brick-red iron oxide, the beach will slowly turn into red sand. When the iron element in magnetite is replaced by aluminum, titanium and other elements, it will be called baute ore, ilmenite and other names. Ilmenite is also an important coastal placer ore, often produced in conjunction with magnetite, lead gray to black, but also the formation of black sand beaches. Ilmenite is often used as a "space metal" in high-tech fields such as aerospace and modern weapons.
Magnetite is the main iron ore
Zircon is a gemstone mineral comparable to diamonds, known in Japan as "hyacinth stone" and is also the birthstone of December. However, not all kinds of zircon can be worn as jewelry: low hardness, low density and low dispersion of "low zircon" is radioactive and is not suitable for wearing. Zircon is the main raw material for the extraction of metallic zircon and hafnium, and the extracted sponge zircon is an important raw material for the structure and cladding of nuclear reactors.
The name monazite sounds a bit lonely, but it is actually lonely during crystallization, often in the form of single crystals, with a brownish-red or yellow-brown color and stable chemical properties. Monazite is one of the main minerals of rare earth metal ore, which can be used for industrial extraction of rare earth elements, and is widely used in electronics, petrochemical, metallurgy, machinery, energy, light industry, environmental protection, agriculture and other fields, with great potential for development.
An inconspicuous grain of sand on the beach, in the long geological time, was washed, eroded, washed, carried... The universe took hundreds of millions of years to create a grain of sand, and every grain of sand is a miracle. Each grain of sand also has its own energy, flowing into the Galactic Nebula, jumping hard, dancing out of the light, making people feel infinite emotion.
monazite
Monazite (Origin: Myanmar) Photo / Dong Jinkun Collection of the Geological Museum of China
Fantasy Adventure – A Treasure Hunt
The Coastal Placer Is Home to a variety of "priceless" associated minerals, so where to look for them?
Coastal placer mines are distributed all over the world, but due to the influence of coastal landforms, material sources and formation processes, the plane distribution is extremely uneven.
Coastal placer mines
The distribution density of coastal placer mines in China from north to south has a sharp increase trend, while there is a trend of local enrichment of monazite, rutile and natural placer gold ore. To find these treasures, be sure to remember the code names "estuary" and "bay", because the most favorable coastal landforms for the formation of coastal placer mines are the estuaries and bay areas.
We started with Guangdong and explored the coast to the north. Coastal placer mines with proven industrial value in the mainland are mainly distributed in Shandong, Fujian, Guangdong, Guangxi and Taiwan, especially in Guangdong, with a large scale of deposits and many mineral species. Guangdong is located in the South China Sea, in south China nonferrous, rare earth metal placer mineralization belt, the same conditions are guangxi, Fujian and Taiwan. The main minerals of this belt placer are cassiterite, zircon, monazite, phosphorus yttrium ore, ilmenite, placer gold, quartz sand and so on. As for Shandong, at the confluence of the Bohai Yellow Sea, it is in the mineralization belt of placer gold and diamond placer ore in North China. The main minerals are gold and diamond, followed by zircon, monazite, magnetite, quartz sand and so on.
We can go to Shandong and Guangdong to find zircon; Go to Liaoning, Shandong to find placer gold...
There are many more treasures to be found on the beautiful colorful beaches, so if you already have your favorite "treasure", pack your bags and go now!
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It does not represent the position of the Institute of Geology and Earth of the Chinese Academy of Sciences
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