For the First Time Ever, Scientists Drill Into the Earth’s Rocky Mantle
As per a recent report from the Washington Post, scientists have successfully reached Earth’s mantle by drilling approximately one mile beneath the ocean floor. This significant accomplishment was made possible by the JOIDES Resolution, an ocean drilling vessel.
It is important to clarify that the scientists did not precisely drill into the mantle, and the drilled hole is not the deepest ever made beneath the ocean floor. Instead, the researchers strategically chose to dig at a specific location in the North Atlantic where the mantle rocks have been brought closer to the surface, known as a “tectonic window.”
Andrew McCaig, one of the expedition’s co-chief scientists, expressed his surprise at the continuous retrieval of dark rock tubes from the drilling process. He shared his excitement, stating that the drilling operation exceeded their expectations.
McCaig mentioned that scientists had been aspiring to obtain a hole of such depth in mantle rock since 1960. The team successfully obtained rock samples from as far down as 4,157 feet beneath the seafloor. McCaig emphasized that this achievement fulfills a long-standing ambition within the scientific community. Now, researchers on land eagerly await the opportunity to examine and study these newly acquired rocks.
“We are incredibly excited about what they have obtained – an incredible collection of rocks,” expressed Andrew Fisher, a hydrogeologist at the University of California, Santa Cruz. Fisher, who has been monitoring the expedition’s progress remotely, shared his enthusiasm for the rock samples acquired by the team.
Drawing an analogy, Jessica Warren, a professor of Earth sciences at the University of Delaware, likened the crust to the icing on a cake, emphasizing that the focus should be on understanding the deeper layers of the Earth. She highlighted the vast amount of rock below the crust that remains to be explored.
Altered Rock Cores Challenge Understanding of Mantle-Crust Boundary
Initial reports indicate that the newly extracted rock cores are primarily composed of peridotite, which is the most common type of rock in the upper mantle. However, the exposure of these samples to seawater has altered their composition, raising questions about the interpretation of the findings. One key question revolves around whether the boundary between the mantle and crust is a distinct separation or a gradual transition.
Andrew Fisher described the extracted rock as a mixture, stating, “It’s a bit of a hash, but that’s maybe what the lower crust is.” He further explained that the samples represent highly altered lower crustal and/or upper mantle rock, spanning over a kilometer in depth. The researchers are particularly hopeful that the deepest samples will provide “fresher” rock, less affected by external processes, and more representative of the composition of the mantle.
Warren concluded that as they delve deeper, they are approaching a closer resemblance to the actual appearance of the rocks and the mantle itself.
Read The Original Article on Interesting Engineering.
Read more: In A First, Investigators Found An Uncommon Mineral That Comes Straight From Earth’s Lower Mantle.
