The block of volcanic rock forced the mountain chain to shift eastward, scientists explain

Jul 19, 2014 20:03 GMT  ·  By
Researchers say the Appalachian mountain chain owes its peculiar bend to rigid volcanic rock in the underground
   Researchers say the Appalachian mountain chain owes its peculiar bend to rigid volcanic rock in the underground

A recent paper in the journal Earth and Planetary Science Letters explains how and why the Appalachian mountain chain in North America ended up being slightly deformed in the section spanning from Pennsylvania to New York State.

The paper, authored by scientists with the College of New Jersey and the University of Rochester, explains that, apart from this peculiar deformity, the Appalachian mountain chain spreads from Alabama all the way to Newfoundland in a fairly straight line.

This is despite the fact that it is about 1,500 miles long (approximately 2,400 kilometers), and had it set its mind to it, would have had plenty of opportunities to show off way more twists and turns that the one bend between Pennsylvania and New York.

By the looks of it, the Appalachian mountain chain owes its anatomical quirk to a block of surprisingly rigid volcanic rock that it encountered just as it was forming and that forced it to shift eastward in the aforementioned region, the specialists behind this research project explain.

As detailed in the journal Earth and Planetary Science Letters, this mountain chain came into being about 300 million years ago, when the North American and African continental plates had one very close encounter with one another. Simply put, they collided.

At the time when this collision occurred, the North American continental plate got pushed upwards and westward, and also started folding. While undergoing these transformations, it encountered a rigid volcanic rock structure that acted as a barricade.

According to the College of New Jersey and the University of Rochester specialists, it was this rigid structure that influenced the birth of the Appalachian mountain chain to a considerable extent. In a nutshell, it kept it from assuming a straight line appearance from beginning to end.

The scientific community has long been aware of the fact that an underground volcanic rock structure can be found in the proximity of the Appalachian mountain chain. “What we didn’t understand was the size of the structure or its implications for mountain-building processes,” researcher Cindy Ebinger nonetheless wishes to stress.

In order to gain a better understanding of how the Appalachian mountain chain as we know it was birthed, scientists measured ground movement in the area and also looked at local fluctuations in the gravitational pull. This is because, contrary to popular opinion, gravity is not a constant and is instead influenced by the density of certain regions of our planet.