Ocean | Minerals | 20th September 2021 | Virtual Wire
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Friends, we all are very well acquainted with the word ocean. We all know that 71% of the earth is covered by Ocean. And this vast Ocean is full of natural resources. The list of natural resources found in the ocean is very long.
The natural resources obtained from the sea have played a very important role in the development of human life. But according to scientists, we know very little about the ocean so far and it will take us much more time to understand it completely. We get many natural resources from the sea which are very important for our daily life like fish, salt, natural gas, oil, etc. But to better understand the natural resources obtained from the sea, we mainly divide it into two parts: biotic and abiotic.
1). Biotic :
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Everything that is in living condition and which humans use to fulfil their necessity is called biotic resources such as corals, reptiles, fishes and mammals, etc.
2). Abiotic :
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Resources that are not in living states are called abiotic resources. They are divided into two parts -
In today's column, I will try to draw your attention mainly to the minerals obtained from the sea. Minerals: Minerals are formed over millions of years as a result of various physical,
chemical, and biological reactions in the ocean. Huge deposits of these minerals are submerged in the sea. Due to the ever-increasing population and its consumption, the reserves of Underground minerals are getting depleted. Due to human attention towards Marine minerals. And for this reason, it becomes important for us to know about marine minerals.
Detailed discussion on marine minerals: Almost all types of minerals are found in the sea. Some of these are found in the dissolved state and some in the deposits of the sea. If we talk about dissolved minerals, then many minerals come into this list such as - NaCl, I2, Br2+,
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Apart from all this, crores of tonnes of gold and silver are also present in a dissolved state in seawater. But due to limited technical resources at present, extraction of gold and silver is not possible. According to an estimate, only 4g of gold can be extracted from about 1 million tonnes of seawater. Therefore, it is not possible to extract gold from the sea even from an
economic point of view.
If we talk about salt, then it comes first in the list of minerals obtained from the sea. 85℅ of the salt of the whole world is obtained from the sea.
If we talk about India, salt is especially found in the ocean areas of Gujarat, Maharashtra, and Tamil Nadu. More than 50% salt of India is found in Gujarat. Now let's talk about some more minerals which are found on different surfaces inside the ocean.
The list of these minerals are as follows -
1). Polymetallic nodules:
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Polymetallic nodules are found in a large part of the deep sea. They are found at the bottom of the sea. They are found at a depth of about 2-5 km at a density of 75 km per square. It is the source of many metals like magnesium, iron, silicate, copper, cobalt, and hydroxide, etc.
These polymetallic nodules mainly contain the highest amount of manganese due to which they are also called "manganese nodules''. Polymetallic nodules are potato-shaped and have massive porous tubules. Their rate of development is very slow. On average, they grow only about 1-3 millimetres in a million years. Other metals such as copper, cobalt, and nickel are also present in these nodules which becomes very important from the industrial point of view.
But the concentration of these metals is very less. It's only 3.0% of the whole weight. Polymetallic nodules are found in all marine areas of the world, but there are the four best known polymetallic nodules fields are the Clarion Clipperton Zone (CCZ ), Peru basin, Central Indian ocean basin ( CIOB ), and Penrhyn basin.
2). Phosphorite :
Phosphorite is a sedimentary rock that contains high amounts of phosphate minerals. Most of the accumulation of phosphorus occurs on the ocean floor. And these accumulation results from atmospheric precipitation, dust, glacial runoff, dust, underground hydrothermal, and deposition of inorganic matter.
The primary flow of soluble phosphorus is from Continental weathering carried by rivers into the ocean. Phosphorite sediments are known as the floor of the Pacific, Indian and Atlantic oceans. Most of the shelf phosphorite provinces are the east Atlantic, west Atlantic, California, and Peruvian - Chilean.
3). Seafloor massive sulfides (SMS) :
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SMS deposits form in the deep ocean submarine volcanic arcs, where hydrothermal vents exhale sulfide-rich mineralizing fluids into the ocean. SMS deposits are laterally extensive and consist of a central vent mound around the area where the hydrothermal circulation exits, with a wide apron of unconsolidated sulfide silt or ooze which precipitates upon the seafloor. SMS deposits contain appreciable grades of precious metals like Cu, Zn, Cd,
Pb, Fe, Pt, Ag, and Au.
3). Placer Minerals :
Placer mineral deposits have been formed by the mechanical concentration of Detroit mineral particles in beaches and offshore areas. These are Detroit minerals that have been transported to their sites of deposition in a particular form. The minerals that constitute the placer deposits are resistant to chemical breakdown and have high density and durability.
Placer minerals include elements in their native state such as gold, platinum, and Diamond. And the resistant minerals such as cassiterite, ilmenite, rutile, zircon, monazite, and Garnett. Placer deposits containing monazite are known on all continents. Monazite has been recovered from placers in Australia, Brazil, India, Malaysia, Thailand, China, New Zealand, Sri Lanka, Indonesia, Korea, and the United States.
4). Oil and Natural Gas :
Oil and natural gas are the main minerals obtained from the sea. The Continental shelves, one of the main parts of the ocean's four seabeds, are rich in oil and natural gas. These are formed where organic matter such as animals and plants borrowed into the ocean floor along with the soil millions of years ago and changed into minerals. The most productive areas for oil and natural gases is the North Sea and the Gulf of Mexico, the Atlantic ocean of
Brazil, and West Africa, the Arabian Gulf, and the seas of southeast Asia. India's offshore fields of oil and natural gas are Bombay High and the Gulf of Cambay.
In the coming times, we are going to be more dependent on ocean minerals. But we need to pay attention to the judicious exploitation of these resources. Because it is a nonrenewable resource and at the same time their excavation damages the biodiversity of the ocean. The recent accident in the Gulf of Mexico also indicates this. That's why we humans should use these precious natural resources not only in view of our needs but also in view of our environment.
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