Have you ever seen a black beach?

People yearn for the sea, like to run on the silver beach on sunny days and let themselves fly. But if you were on a dark beach, how would you feel?

On the long coastline of China, there are many beaches, mostly yellow, silver and white, but there are also some black beaches that are rare in some areas. Under the sunshine, the beach is no longer bright and glamorous, but deep and solemn, as if telling the story of the years affectionately …

Black beaches are rarely seen.

If you have a chance to travel all over the coastline of China, you will find that there are few black beaches. Guangdong's coastline is quite long, with more than 4 100 kilometers, but if you count carefully, there are only a few black beaches: the most famous one is Taishan Heishan Bay, which is located in Tonggu Bay, Chixi Peninsula, Taishan, with a coastline of 1.5-2 kilometers; To the west of Heishan Bay, there is also a small piece of black sand beach in Qinlongwan, Taishan, which is about 90 kilometers apart. The difference is that Longines Bay is "yellow and black", with yellow sand beach in the east and black sand beach in the west.

In addition, the southern side of Macao Island is the southernmost tip of Prince Peninsula, which is a large natural beach around Macao, including a small black beach, which is a relatively rare black beach around the city. As for other famous black beaches in China, the black beach in Qijin Peninsula at the southwest end of Kaohsiung, Taiwan Province is one, and there is also the white beach in Fangchenggang, Guangxi. There are even fewer others who can't name them.

There is little domestic experience, and netizens have a lot of exposure to those foreign black beaches. The most famous is Renis Black Beach in Vik at the southernmost tip of Iceland, followed by Punalu'u Beach in Hawaii, Jeju Island in South Korea, Lovina Beach in Bali and Tahiti Island in the South Pacific.

Among all these black beaches, Renis Black Beach in Iceland was once chosen as the most beautiful beach in the world. The black sand beach here is not only large in area, but also exquisite. If you throw away a handful of black sand in your hand, pat your hand clean and don't turn black. Dark black gives the black beach a sense of mystery.

There is also a legend of "taking away the black sand and dying of natural causes" on the black sand beach in Hawaii. It is said that the indigenous Polynesians in Hawaii rose up against foreign invasion, and one of the chiefs put a curse before he died: whoever takes a grain of sand and a stone from Hawaii's land will not die a natural death. Therefore, if someone takes sand from the black beach in Hawaii, he may encounter an "accident". It sounds like this black beach is a bit "black terror"; But at the same time, it also reminds people from the side that we should cherish the original resources of nature and don't "move our brains."

Black sand beach is "the footprint of volcano"

"Things are scarce", people are curious about the color of the black beach, and even more curious about how this black beach was formed.

There is a coal-fired power plant near Heishan Bay in Taishan. At one time, people even doubted whether the cinder left after power generation caused the beach to turn black. According to experts' research, the black beach existed before the power plant was built. Obviously, this "blackened" "pot" cannot make the power plant innocent.

Most people's first instinct is that the formation of black beaches is related to volcanoes. Yes, wherever there is a black beach, it is related to volcanic activity to some extent; Moreover, the more frequent volcanic activity, the more black beaches. To put it simply, after a volcano erupts, magma spews out and condenses rapidly after encountering seawater, forming large and small volcanic rocks. Because of the blackening after burning, volcanic rocks were "polished" by seawater for a long time, from large to small and then thin, and finally became a black beach.

The black sand beach in Renis, Iceland is a wonder of the world, because Iceland itself is the location of active volcano, and volcanic activity continues. Vik is located in Mirdas Glacier Covered Area, under which is catra Volcano, and needs to wake up from time to time to get some air. Until now, the residents of Wake Town regularly organize various exercises in order to prevent volcanic enthusiasm from erupting one day and how to protect themselves. As for Hawaii and Jeju Island, it is obvious that these two places are veritable volcanic islands, including Bali.

Crustal movements are not only volcanoes, but also earthquakes. The appearance of black sand beaches along the South China Sea in Guangdong Province means that there were similar signs of crustal activity in this area in ancient times. According to the research results of geologists, "during the late Triassic-Paleogene, there were strong multi-stage magmatic activities and tectonic movements in the coastal areas of western Guangdong. Among them, the deep magma is rising, invading or erupting along the Heshan-Jiangmen-Zhuhai-Shenzhen-Hong Kong line, accompanied by many times of extensional-contractive structural deformation, forming a NE-trending tectonic magmatic rock belt. All kinds of granites exposed along the coast of Black Shawan in Tonggu are the products of this tectonic-magmatic background.

Often accompanied by black sand beach phenomenon, there are "columnar joints." Jules verne, a French science fiction writer, once described the columnar joints in Journey to the Center of the Earth, saying, "The nature here has geometric features, as if it had been carved by hand, as if it had been painted with a square, compasses and vertical lines ..." Regular arrangement, long or short, neatly stacked prismatic columns can be seen everywhere in Vic Beach and Jeju Island in Iceland. This is also due to the fact that when the volcano erupts, the basalt rapidly cools into a solid state when it meets seawater, and the crystals contract, forming regular columns side by side on cliffs and coasts. Volcanic lava will not be ejected once, but wave after wave, and the cooled pillars will form a multi-level structure.

Most of the black beaches were born in quiet bays.

Volcanoes create the most basic conditions for the formation of black beaches. The volcano pushes the burning basalt lava to the sea, and the lava cools rapidly when it meets the sea, and some become columnar joints and fall around the coast; Some intrude into other geological structures and become hidden "veins"; Others may be scattered like stones.

Scientists have found that the formation of black sand beach is closely related to coastal landform, the material composition of coastal bedrock and its seawater dynamic conditions. But whether the black sand beach can finally be formed depends on the nature. First of all, there must be a "black enough" material. Scientists first use the simplest method to determine the composition of black sand beach: select a small amount of ordinary sand and black sand, and add dilute hydrochloric acid. It can be clearly seen that the reaction of ordinary sand is quite intense, while that of black sand is not so intense. This shows that the composition of these two substances is very different.

Further research found that the main component of black sand beach is biotite, not calcium carbonate of ordinary sand. The sand grains on the black sand beach in Black Shawan, Tonggu, Taishan are composed of flaky biotite. Coastal bedrock composed of biotite granite may become chlorite, hydrobiotite and vermiculite or glauconite after long-term weathering. Glauconite veins were found near some black beaches along the coast of Jiangmen. There are either these cornerstones around the black sand beach, or a large number of biotite sediments are brought into the sea by rivers and deposited near the estuary.

Even if these stones exist around the coast, not all stones can form a black beach. The black sand beach needs a relatively calm bay between two headlands. Only in this way, reducing the energy of wave and tidal impact is beneficial to the continuous "polishing" of sand particles with biotite composition by seawater and the precipitation of fine sand particles; If the coastal areas are relatively open, the water is fast and the hydrodynamic force is too strong, it is difficult to accumulate flaky biotite fine sand and finally it is difficult to form a black beach. Mount Tai Black Bay is surrounded by mountains on three sides and faces the sea on the south. It is located in a small bay concave to the land in the coastal zone of Tonggudian, which coincides with such geological characteristics. Macau Road Ring Beach and Kaohsiung Qijin Peninsula Black Beach were also formed in calm bays.

Black mica mainly exists in fine sand, silt and other fine particles, which is also the main reason why black sand beach generally makes people feel fine and soft when stepping on it. The waves in the bay are gentle and the sand grains are fine, and all the black beaches are suitable for relaxation-this is really a sigh of nature, leaving people with a very beautiful "black space". In addition to sightseeing and leisure, some black beaches may also contain special trace elements and become natural physical therapy resorts.

Black sand beach will "change face"

Due to the different sandy composition, the "natural black" of black beaches is also divided into different grades. Scientists found that "chloritization is widespread at the edge of biotite, and even some particles have obviously turned into chlorite or hydrobiotite. The difference of biotite content in different sand chips causes the change of beach color. "

The black beach reminds people that the beach will "change face". In the world, in addition to black beaches, there are pink, red, matcha and even amber "colored beaches". The principle is basically the same, because the material composition of the beach area is different, which leads to colorful.

There is also a "color-changing factor", which is light. In fact, the black beach is not "black to the end". Scientists observed with a microscope in the laboratory that biotite is a little brownish or dark green with obvious polychromatic color, but only under the conditions of natural beach lighting and environment does it show a color tone dominated by black. Colorful beaches often contain rare elements, showing a layered sense of color gradient under different lighting conditions.

No matter what kind of beach it is, it is a gift from nature, and the rare colored beach is worth cherishing. Cherish this gift from nature and protect her.