Echoes from ancient Earth: Zircon clues reveal Easter Island's hidden volcanic history | Travel News
A recent geological study involving researchers from Cuba, Colombia, and Utrecht University has uncovered surprising evidence that challenges traditional views on Earth's mantle dynamics. The team found zircon minerals on Easter Island that show signs of volcanic activity dating back 165 million years, suggesting the mantle beneath the island may behave differently than previously thought.
Easter Island’s volcanic history, marked by extinct volcanoes, dates back about 2.5 million years. However, new zircon dating led by Cuban geologist Yamirka Rojas-Agramonte revealed minerals much older than expected, some as old as 165 million years. This raises questions about the origins of these minerals, as the oceanic plate beneath the island is much younger.
Further analysis indicated that the zircon minerals share a composition similar to modern volcanic magma, hinting that these ancient minerals originated in the mantle long before the island’s current volcanoes formed. This discovery complicates the understanding of "hotspot volcanoes" like Easter Island, where mantle plumes rise from deep within the Earth.
Rojas-Agramonte collaborated with Utrecht geologist Douwe van Hinsbergen to explore past geological events in the "Ring of Fire," a tectonically active region. Van Hinsbergen's reconstructions revealed that a volcanic plateau near Easter Island 165 million years ago subducted beneath the Antarctic Peninsula. This event, along with other significant geological changes, suggests that the Easter Island mantle plume could have been active for far longer than previously believed.
These findings challenge the classical "conveyor belt" model of a constantly moving mantle. The presence of ancient zircons implies the mantle around the plume may be more stationary, allowing these minerals to persist near the surface. This research builds on earlier studies from the Galapagos and New Guinea, shedding new light on Earth's mantle dynamics.
