Scientists have discovered a hot blob of abnormally hot rock beneath the Appalachian Mountains, which they believe formed when Greenland separated from North America around 80 million years ago. The blob, known as the Northern Appalachian Anomaly, sits 125 miles deep and stretches 220 miles across New England.
Research suggests that this hot zone has been moving at a rate of 12 miles per million years and is currently heading towards New York. The team used direct geological observations and computer simulations to model plate tectonics and geodynamics, finding that the blob’s movement was consistent with previous estimates.
The formation of the hot blob is believed to be caused by material from Earth’s mantle rising to fill gaps in the crust left by rifting. This material eventually cools and becomes dense, setting off chain reactions in the mantle known as “mantle waves.” The researchers found that such blobs occasionally form in continent breakups, with possible knock-on effects for mountains, volcanoes, and ice sheets.
The study’s findings suggest that hot blobs can continue to influence the planet for thousands of years after a continent breakup. They also provide insights into why some ancient mountains remain so high despite major erosion over time.
According to researchers, the movement of the hot blob may have helped uplift the Appalachian Mountains when it reached its current location. The study’s authors believe that such blobs could explain why similar geology is still present in other mountain ranges and rare volcanic eruptions that bring diamonds to Earth’s surface.
The Northern Appalachian Anomaly will continue on its path towards New York over the next 10-15 million years, after which the crust will settle again. The study highlights the ongoing influence of ancient geological events on the planet’s dynamics.
Source: https://www.livescience.com/planet-earth/geology/hot-blob-beneath-appalachians-formed-when-greenland-split-from-north-america-and-its-heading-to-new-york