The collision between the americas happened earlier than previously thought

Magnetic evidence hints that key tectonic processes in the Andes had already waned, revealing new potential in geophysical methods to decode Earth”s past. Credit: Shutterstock

doi.org/10.26464/epp2026011
Credibility: 989
#Tectonism

A new study by geologists is changing what we knew about the formation of the Andes

According to the research, the great collision between Central and South America ended much earlier than previously thought-before about 10 million years ago.

Scientists analyzed ancient volcanic rocks from the Combia Volcanic Province in central Colombia.

These rocks, formed between 12 and 6 million years ago, at the end of the Miocene, hold magnetic “fingerprints” that reveal what was happening inside the Earth at that time.

By studying the orientation of magnetic minerals within these rocks, researchers were able to distinguish the original magma flow patterns from those caused by later deformations caused by the movement of tectonic plates.

The result was surprising: most of the rocks still preserve their original structure, indicating that they underwent little or no significant deformation during the late Miocene.

This means that the major events of shortening and deformation of the Earth’s crust, related to the collision between the two continents, had already ended earlier.

The most intense processes likely occurred between the Oligocene and the middle of the Miocene, that is, millions of years earlier than previous models suggested.

“The data show that the most significant events of the collision between Central and South America happened earlier than we imagined,” the researchers explain.

“When these volcanic rocks formed, tectonic deformation was already weaker and restricted to smaller areas.”

This discovery refines the understanding of how tectonic plates shaped the Andes mountain range and the landscape of the region.

Furthermore, the study highlights the value of magnetic techniques for reconstructing geological history in volcanic environments, offering a powerful tool for deciphering Earth’s past.

With this, scientists now have a more precise view of when and how the Americas joined together, which helps to better explain the evolution of the mountains and the environments around them.

Published in 04/16/2026 00h51

Portuguese version

Text adapted by AI (Grok) and translated via Google API in the English version. Images from public image libraries or credits in the caption. Information about DOI, author and institution can be found in the body of the article.

Reference article:

Original study:

{teste}