An ancient slab of seafloor has been discovered beneath the Pacific Ocean, where it has remained for over 120 million years. This discovery sheds light on geological processes deep within the Earth and helps explain a mysterious gap in the mantle layer.
Deep beneath the Earth’s surface, there are two massive blobs of hot material rising from the outer core into the mantle layer. These large low-shear-velocity provinces (LLSVPs) can’t be seen directly but are inferred from seismic imaging techniques. One of the well-known LLSVPs is located beneath the East African Rift Valley.
The newly discovered seafloor slab under the Nazca plate in the Pacific Ocean provides insight into the complex interactions between tectonic plates and mantle structures. This ancient slab, which dates back to the time of Earth’s earliest dinosaurs, is slowly sinking into the Earth’s mantle at a rate of 0.5 to one centimeter per year.
Scientists believe that the presence of this ancient seafloor slab in the mantle blob gap could be due to tectonic reshuffling or subduction processes that occurred millions of years ago. The thickness of the slab and the viscosity of the mantle region play a role in determining its slow sinking speed.
Understanding the history of plate tectonics over the past 250 million years is crucial for unraveling Earth’s complex past. The discovery of this ancient seafloor slab provides valuable clues about the planet’s geological evolution and the processes that shape its subsurface.
By studying these deep-seated geological structures, scientists can gain a better understanding of the Earth’s dynamic processes and how they influence surface events such as volcanism. The presence of ancient relics like the seafloor slab beneath the Pacific Ocean highlights the interconnected nature of Earth’s geological history and the ongoing processes that shape our planet.
