A long sample of rocks from the Earth’s mantle can help unravel the mysteries of the formation of our planet and the origin of life on it.
Scientists have obtained the first long sample of rocks originating from the Earth’s mantle, the layer beneath the crust that makes up the largest part of the planet. This finding may reveal the role of the mantle in the origin of life on Earth, volcanic activity, and global cycles of important elements such as carbon and hydrogen.
The team of researchers extracted a nearly continuous 1,268-meter-long sample of mantle rock from a «tectonic window» — area of the seafloor where mantle rocks are exposed along the Mid-Atlantic Ridge. This occurred during Expedition 399 «Building Blocks of Life, Atlantis Massif» on the drillship JOIDES Resolution in the spring of 2023.
Prof. Johan Lissenberg of Cardiff University, lead author of the study, reported unexpected results of the sample analysis.
«The rocks contain much less pyroxene mineral, and the magnesium concentration is much higher than we expected. This indicates more intense melting than expected,»,” the scientist explained.
These discoveries could have a significant impact on the understanding of magma formation and volcanism. The researchers found channels through which the melt moved through the mantle.
«This will help us understand how the mantle melts and feeds volcanoes, especially those on the ocean floor,» added Prof. Lissenberg.
The study of the samples also showed how olivine, a common mineral in mantle rocks, reacts with seawater to form hydrogen and other molecules that could support life. Scientists believe that this could have been one of the main processes in the emergence of life on Earth.
Dr. Susan Q. Lang of the Woods Hole Oceanographic Institution said:
«Analyzing these rocks gives us a critical look at the chemical and physical conditions that existed on the early Earth and could have provided a constant source of energy for the earliest life forms».
An international team of more than 30 scientists will continue to study the recovered samples to address a wide range of questions in fields ranging from mantle melting processes to organic geochemistry and microbiology.
As a reminder, geologists from the University of Southampton (UK) have discovered that high plateaus in the interior of continents are formed by processes that occur deep inside the Earth hundreds of kilometers from the place of their formation.
Source: Phys, Livescience, Science