A new study has revealed that the collision between Central and South America happened millions of years earlier than previously believed. Scientists focused on volcanic rocks in Colombia's Northern Andes, particularly in the Combia Volcanic Province, to better understand the timeline of tectonic interactions. Led by researchers Victor Piedrahita and J. Li, the study analyzed the magnetic properties of volcanic rocks from the late Miocene period, which is approximately 12 to 6 million years ago, to determine when tectonic forces began to reshape the region. The researchers used a technique called magnetic fabric analysis, which examines how magnetic minerals are aligned in rocks. This alignment can reveal information about the forces that shaped the rock, such as magma movement or volcanic debris flows. The findings showed that many of the volcanic rocks studied had magnetic structures that remained largely unchanged, indicating that they experienced little to no significant tectonic deformation during the late Miocene. However, some areas did show signs of deformation, but these were limited in both intensity and geographic reach. The study suggests that the most intense tectonic compression between Central and South America had already occurred before the late Miocene, likely during the Oligocene to middle Miocene periods, which are roughly 34 to 15 million years ago. This challenges earlier assumptions about the timing of major tectonic events in the region and could lead to more accurate models of the Andes' formation and the geological evolution of the Americas. The research was supported by the National Natural Science Foundation of China and contributes to a broader understanding of how tectonic plate movements have shaped the Earth's surface over millions of years. By refining the timeline of these events, scientists can improve predictions about future geological changes and better understand the forces that continue to shape our planet.