Trovants are bulbous, otherworldly stones that grow over time, thus appearing to be alive. Parent rocks can even push out baby trovants, which then grow independently.
The sandstone structures are found mainly in Romania, with the most famous cluster in and around a village named Costeşti. There, a Trovants Museum Natural Reserve celebrates and protects them.
The stones’ smooth curves give the appearance of modern, man-made sculptures. They feature heavily in local folklore, with people at one time believing them to be giant dinosaur eggs, plant fossils or alien creations. The word trovant was coined by a naturalist and means cemented sand.
The stones are formed from sand grains or rocks bound together by a limestone – calcium carbonate – cement. Geologists think that the trovants were shaped by earthquakes in the Middle Miocene, over five million years ago.
The stones vary greatly in size and shape, from centimetres to metres in diameter. Whereas most rocks erode and reduce in size over years, trovants continue to expand. During heavy rain, the porous trovants absorb substances, including calcium carbonate from the water. Limestone cement then oozes from the stones to add to their circumference. When water only hits one side of a rock, a blob can emerge, finally breaking free to create a new trovant.
Trovant growth is too slow to be watched in real time. It is estimated that the rocks have only grown a handful of centimetres in over 1,000 years.
The sandstone beds that the stones reside in hint at ancient aquatic environments, with successive sedimentation of material transported by rivers. Indeed, bivalve, and gastropod fossils can sometimes be found hidden inside the trovants.
Read more:
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- For those who like to rock: The most interesting rock formations on the planet
Asked by: Zara Webb, Stafford
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