The data obtained on Pleistocene sediments can be used to clarify the chemical composition of the earth's crust
The chemical features of sedimentary deposits of the Atlantic Ocean, formed in the Pleistocene more than 2 million years ago, were studied by Russian scientists from the Institute of Geochemistry and Analytical Chemistry named after. IN AND. Vernadsky RAS (GEOKHI). The intensity of accumulation of various elements in this water area turned out to be greater than in other oceans. This work was a continuation of many years of research by scientists on the bottom sediments of the World Ocean.
The drilling vessel Joides Resolution (USA), which obtained most of the deep-sea drilling samples used in the article. Photo by J.-A. Flores (Spain), from the personal collection of M.A. Levitan.
MK Help. The Pleistocene Epoch (often informally referred to as the «Ice Age») is an era that began 2.588 million years ago and ended 11.7 thousand years ago.
First, a little background. The US and USSR began the project of deep-sea drilling of the ocean floor in 1968. From our country, the project was represented by the Institute of Oceanology named after. Shirshov of the USSR Academy of Sciences, from the States — an association of oceanographic institutes. Over the 55 years of work by scientists of the project, which subsequently included more than 25 countries, a lot of material was collected on the composition of Pleistocene sediments on the bottom of various oceans. But no one except our scientists has collected all the knowledge together. In 2021, this was done by a group led by Mikhail Levitan, Doctor of Geological and Mineralogical Sciences, Head of the Laboratory of Geochemistry of Sedimentary Rocks of the Geochemistry Institute of the Russian Academy of Sciences.
“This was a generalization on Pleistocene deposits,” says Mikhail Arkadyevich. We worked with data on the Pacific, Indian, Atlantic, and Arctic oceans, on rocks recovered from different depths on the shelf, on continental slopes, rises, and the global floor of all oceans. We did not touch only the ultra-deep-sea trenches.
– What is said in your new article, published in Lithology and Mineral Resources?
– In the latest work, which was carried out on behalf of the Russian Ministry of Education and Science, we moved from the main conclusions on the composition of sediments — sands, clays, carbonates and etc. – to their chemical composition. And again they found themselves in first place in the world, because no one had ever made such generalizations.
– And how does the chemical composition of Atlantic sediments differ from other oceans?
– For now, we can only compare it with the Indian Ocean, on which we published a publication in 2023 (work on the Pacific and Arctic oceans is still underway). To begin with, I will say that the intensity of accumulation of various elements in the Atlantic turned out to be noticeably greater than in other oceans.
If we talk about what is more abundant in the Atlantic Ocean, we can highlight carbonates (CaCO3). There are a third more of them than in Indian. But the Indian Ocean surpasses the Atlantic in the distribution of so-called red clays — the deepest and slowest-accumulating sediments in the World Ocean. They contain fields of ferromanganese nodules — potential minerals: manganese, copper, nickel, zinc and cobalt. The red clays themselves are potential raw materials for the search for rare earth elements, the interest in which is very great in the world.
As for the study of Pleistocene sediments in the Pacific and Arctic oceans, they will allow scientists to generalize knowledge about the geochemistry of bottom sediments and contribute contribution to the study of the chemical composition of the earth's crust as a whole.