What can be found deep in bowels of Earth?

By Rushan Ziatdinov

Natural resources hold great significance for each country, particularly to their own national economies. They are the basis for the production of goods that are then exported, and thereby contribute to the country's economy. They are highly valuable in terms of national income and the alleviation of poverty. The availability of natural resources creates jobs for people, and are often a major source of livelihood, particularly in rural communities.

When a country has meager resources, scarcities may occur. In the simplest of terms, as defined by National Geographic, that means the demand for goods or products is higher than the goods or products on hand. Each country has its own primary resource(s) that it uses to produce goods and services. When dealing with scarcity, equilibrium can be restored by distributing resources from one place to another.

According to National Geographic, traders with private companies or governments are to blame for the dispersal of available resources. They produce an equilibrium between the needs and/or wants of the consumers, the needs of the government, and effective and precise resource usage in order to be able to utilize income gains to the fullest. Additionally, export-import relationships are organized with other countries.

As is known, the Earth is divided into different layers with four major components, namely the crust, mantle and the core, which is divided further into the outer and inner core. The upper layer, called the lithosphere, is made up of the crust and the upper mantle, and is inflexible and stiff. It is divided into different tectonic plates and there are several known resources present that are regarded with high importance, like gold and iron. Also found in the lithosphere are resources that are necessary for the production of energy.

In the deeper layers of the bowels of the Earth lies the lower mantle, also known as the mesosphere, which is made up of silicon and magnesium. Some resources that can be found in this part of the Earth include silicate perovskite, silicon, iron, oxygen, olivine, pyroxene and ferropericlase.

Several different projects have been conducted over the years by scientists and other professionals from various fields in the pursuit of unearthing and exploring the deep layers of the Earth. Firstly, there was Project Mohole, which took place from 1958 to 1966 in the United States. It was an attempt to gain access to material samples that came from the mantle of the Earth through drilling a hole from the Earth's crust to the Mohorovicic discontinuity, as stated by the U.S. National Academy of Sciences.

Sadly, Project Mohole proved to be unsuccessful, with the deepest hole drilled being 183 meters below the ocean floor. Still, it was a victory in showing how drilling a hole in the deep sea floor provides a feasible way of generating geological samples.

There's also the SG-3 Kola Superdeep Borehole, which is known as the deepest hole ever drilled on Earth. The execution of this project took place in 1970 by Soviet scientists near Murmansk in the then-USSR. Their goal for the project was to drill as deep as possible into the crust of the Earth, as stated in a 2020 article in Energy Global News. The target depth was 15,000 meters. The project began on May 24, 1970, by means of the Uralmash-4E drilling rig, later replaced by the Uralmash-15000. Via these means, a main hole was drilled from which further holes were rooted.

According to a 2020 Energy Global News article, the project's process was slow and involved drilling incidents, scientific investigations and a hunt for possible technical solutions. In 1989, the approximately 22cm-diameter hole was recorded to be 12,262 meters in depth. Researchers discovered water 12 km deep in the Earth's crust, proving what had been thought previously to be impossible. Additionally, 24 different types of dead single-celled organisms were discovered, along with access to 2.7 billion-year-old rocks. A fascinating finding from the Kola Superdeep Borehole was microscopic plankton fossils.

Recent research by Prokofiev et al., published in Scientific Reports in 2020, shows that gold-bearing Archaean rocks have been discovered at depths of 9,500 meters to 11,000 meters in the Kola Superdeep Borehole (SG-3, 12,262 meters). Quartz has been found to have fluid inclusions with gold nanoparticles in veins between 9,052 meters and 10,744 meters deep within this gold zone. The authors state that different types of fluid inclusion are present: liquid-vapor-halite, liquid-vapor, liquid-vapor-CO2 and pure CO2 in quartz veins, all containing exceptionally high concentrations of gold and silver.

The extraction of resources will not only benefit countries' economies and people, but could also contribute to the attainment of several different Sustainable Development Goals. Countries with meager resources may therefore profit significantly if they think more about investigating the deeper bowels of the Earth.

Rushan Ziatdinov (ziatdinov.rushan@gmail.com) is a professor in the Department of Industrial Engineering at Keimyung University in Daegu.