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Giant Ancient Blobs in Earth’s Mantle Could Be Over a Billion Years Old

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Massive continent-sized structures buried deep within Earth’s mantle may be more than a billion years old, shedding new light on the planet’s internal dynamics. Known as large low-seismic-velocity provinces (LLSVPs), these formations are distinct from the surrounding mantle due to their unique physical and chemical properties. Located at the boundary between the mantle and the outer core, roughly 3,000 kilometers beneath the surface, these enigmatic structures have intrigued scientists for decades. Their ability to slow down seismic waves suggests they are compositionally different, possibly containing denser or hotter materials than the rest of the mantle.

A recent study published in Nature analyzed seismic data from over 100 significant earthquakes to investigate these deep-mantle structures. As reported by Space.com, Utrecht University seismologist Arwen Deuss explained that while it was well known that seismic waves slow down in these regions, an unexpected finding was that the waves also lose less energy than anticipated. This suggests that temperature alone cannot account for the properties of LLSVPs, indicating that other factors—such as mineral composition or internal structure—play a role in their formation and persistence over geological time.

One of the key insights from the study is the role of crystal size in influencing how seismic waves behave within LLSVPs. Computer simulations suggest that seismic energy is affected by the grain boundaries between crystals, with smaller crystals leading to greater energy loss and larger crystals allowing waves to pass with less resistance. Deuss noted that while the surrounding mantle consists of fragmented tectonic plates that have broken down over time, the LLSVPs appear to have remained relatively undisturbed, preserving their larger crystal structures for over a billion years.

These findings offer a new perspective on the deep interior of Earth and its geological evolution. Understanding LLSVPs is crucial for unraveling the processes that shape mantle convection, plate tectonics, and even volcanic activity at the surface. Further research into these massive formations could help explain the role they have played in Earth’s history, including their potential connection to supercontinent cycles and deep-mantle plumes that drive hotspot volcanism.

Romania’s Mysterious ‘Living’ Rocks Grow and Multiply Through an Unusual Natural Phenomenon

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In the heart of Romania, near the village of Costești, a fascinating natural phenomenon has captured the curiosity of both scientists and locals alike. These peculiar geological formations, known as trovants, have been making headlines due to their unique characteristics that seem to defy conventional understanding of rock formation. Resembling smooth, bulbous stones, trovants are said to grow and even reproduce over time, a feature that has given rise to numerous myths and legends. Some have likened them to dinosaur eggs, alien artifacts, or even plant fossils, but their true nature is rooted in a fascinating geological process.

Trovants are primarily composed of a solid stone core encased in a porous sandstone shell. This outer shell has the ability to absorb minerals, especially calcium carbonate, from rainwater. The process causes the rock to expand slowly, adding roughly 5 centimeters to its circumference every 1,000 years. Over time, the rocks may develop lumps on their surface that can eventually break off, forming new trovants. This ongoing expansion and reproduction of the rocks is one of the reasons they’ve been referred to as “living” rocks, although the phenomenon is actually a result of a unique combination of minerals and environmental conditions rather than biological processes.

The origins of the trovants are tied to ancient geological events that occurred more than 5 million years ago. Seismic activity, including earthquakes, played a significant role in compacting sedimentary deposits in an aquatic environment, eventually leading to the formation of these spherical structures. Fossils of bivalves and gastropods found within the trovants suggest that the rocks may have formed in a marine setting, adding further credence to this theory. While similar formations have been documented in other parts of the world, such as Russia, Turkey, and the United States, Romania’s Costești region is home to the largest and most famous trovant deposits.

Despite their oddity, trovants are a fascinating example of how nature can produce strange and beautiful geological features. The slow yet constant process by which they grow and multiply offers a window into the dynamic forces that shape the Earth’s surface. While the legend of the “living” rocks may remain a source of intrigue, scientists continue to study these formations to better understand the complex interplay of minerals, water, and environmental conditions that lead to their creation