Title: "Unraveling the Enigma of Colombia's Sierra Nevada de Santa Marta: The Lost 'Roots' that Defy Gravity"
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| Colombia's Majestic Sierra Nevada de Santa Marta: Soaring Beyond 18,000 Feet (Image credit: Georg Rubin via Getty Images) |
New research reveals that the northern Sierra Nevada de Santa Marta mountains in Colombia once had a robust crustal "root" supporting their towering peaks. However, this geological foundation seemingly disappeared into the mantle millions of years ago, leaving scientists puzzled about the mountains' ability to remain standing. The Sierra Nevada de Santa Marta, characterized by peaks exceeding 18,700 feet (5,700 meters), has intrigued geologists since the 1970s when measurements indicated an unusually thin crust beneath the peaks.
Study lead author David Quiroga, a data scientist and former graduate researcher in geophysics at the University of Alberta, explained that mountain regions typically boast thick crustal roots compensating for the load of the mountains. In this case, the elevated positive gravity anomaly in the Sierra Nevada de Santa Marta suggested an excess of mass rather than the expected deficit, indicating the absence of a crustal root.
The study proposes that the mountain range lost its crustal root over a period of 10 million years, with the material sinking into the mantle. This process, known as lithospheric dripping, occurs when the lower lithosphere, heavier and colder than the underlying mantle, descends, causing changes in crust composition and sinking.
While previous research has suggested similar mechanisms in other regions, the Sierra Nevada de Santa Marta presents a unique case. The study's models suggest a recent loss of support, possibly within the last 2 million years, challenging the expectation of a prompt collapse following root removal.
The researchers speculate that additional factors, such as the strength of the surrounding lithosphere and the rising mantle, may have contributed to the mountains' current upright state. Factors like the Caribbean tectonic plate sliding beneath Colombia could also be crucial in future models.
Despite advancements in understanding, the mystery surrounding the Sierra Nevada de Santa Marta persists, raising intriguing questions about the geological forces that have allowed these mountains to defy expectations for millions of years.
