Scientists from the United States have discovered traces of a disappeared ocean and a collision of tectonic plates that occurred hundreds of millions of years ago. The consequences of a geological event were found in the American city of Baltimore.
Today, the local highlands do not stand out as clearly as the Grand Canyon or the Fjords of Norway, but, according to geologists, they appeared when fragments of the earth’s crust came to the surface.
George Geis, an employee of the National Museum in Washington DC, says that such places are extremely rare and unique. The research has already been published in scientific journals. As it turned out, geologists assumed that the rocks in Baltimore may contain fragments of the oceanic crust and lower layers of the mantle. Only a chemical analysis of the rocks confirmed their guesses
“We can’t see a huge chunk of the geologic formation because a large old city is built on top of it. However, it’s worth noting that such windows into the earth’s crust are relatively rare,” said lead author George Geis of the National Museum of Natural History in Washington. …
The scientists published the results of their research in the journal Geosphere. Geologists have long assumed that the rocks in this region contain fragments of ophiolite – parts of the oceanic crust and an underlying layer of rocks – the mantle that has been pushed to the surface. But now, after chemical analysis, evidence for this theory has been obtained.
The rich geological history of the Earth is behind it all, they said. During the formation of the planet, continental masses collided with each other and diverged, oceans appeared and disappeared, and the world itself was in continuous, albeit slow, movement. For example, the Appalachian Mountains in the eastern United States were formerly part of the same ridge as the Scottish and Moroccan mountains, according to phys.org.
The ocean that gave birth to the fragments of the Baltimore ophiolite is the long-vanished Iapetus. About 460 million years ago, Iapetus began to close as various continental masses began to converge, and the rocks became higher, eventually forming the Appalachians.
The Baltimore area is part of a geological belt running from northern Alabama to Newfoundland, which was part of this formation. Scientists noted that less is known about the central and southern region than about the northern. This is partly due to the fact that the cliffs in Newfoundland are more exposed.