A lost continent lies in pieces beneath southern Europe. Geologists call it Greater Adria: a Greenland-sized landmass that was crushed under Europe, leaving its scraped-off remains scattered through the mountains of Italy, Greece and the Balkans.

A lost continent lies in pieces beneath southern Europe. Geologists call it Greater Adria: a landmass roughly the size of Greenland that broke off the supercontinent Gondwana, drifted north for tens of millions of years, then collided with Europe and was driven down into the mantle. What remains was scraped off the top during that collision and now sits folded into the mountains of Italy, Greece and the Balkans.

The detailed picture comes mainly from one large piece of work: a 2019 reconstruction published in Gondwana Research by Douwe van Hinsbergen of Utrecht University, with colleagues in Oslo and Zürich. The existence of a buried Adriatic continent was not the new part. Geologists had understood the broad outline for decades. What the paper added was detail: a time-lapse reconstruction of the whole Mediterranean, assembled slice by slice.

What the study actually did

The reconstruction took about ten years. Van Hinsbergen has described the task as a jigsaw whose pieces had been broken, curved and stacked on top of one another, then scattered across more than thirty countries from Spain to Iran, each with its own geological surveys and its own maps. He has called the region, plainly, “a geological mess.”

The team used plate-reconstruction software together with field data and the magnetic orientation locked into rocks at the moment they formed. Those tiny palaeomagnetic signals act as a record of where a rock sat, and which way it faced, in the distant past. Reading them across thousands of samples let the group wind the deformation backwards and watch the region reassemble.

What Greater Adria was

Here the “lost continent” label can mislead. Greater Adria was not a green, populated land that sank like the Atlantis of legend. For much of its life it was largely underwater: a shallow continental shelf in a warm, tropical sea, where sediments settled and slowly hardened into limestone. The closest living comparison is Zealandia, the mostly submerged continent whose few high points are New Zealand and New Caledonia.

It broke from Gondwana about 240 million years ago, in the Triassic, and drifted north. By around 140 million years ago it had reached roughly the size and shape of Greenland.

Then, between about 100 and 120 million years ago, it ran into Europe.

How a continent disappears

Continental crust is generally too buoyant to sink. That is the usual rule, and it is part of why this story is unusual. When Greater Adria met Europe, most of the continent was forced down beneath it, into the mantle, where it remains. Only the uppermost layers, the lighter sedimentary rock, were too light to follow. They were peeled off in the collision, the way a sleeve crumples when an arm is pushed under a table, and left piled into the mountain belts that run through the region today.

Some of that scraped-off rock is familiar. Limestone from Greater Adria, cooked under heat and pressure, became the marble that the Greeks and Romans quarried for their temples. The continent did not vanish without trace. It became scenery, and then it became building stone.

What is solid, and what is a model

The reconstruction is detailed, but it is a reconstruction. Laurent Jolivet, a geologist at Sorbonne University who was not part of the work, told Science that the broad tectonic history had been known for some time, and that the achievement here was the unprecedented level of detail in the systematic time-lapse model.

That distinction matters for reading the result. The northward drift, the collision and the burial rest on a large body of structural and palaeomagnetic data, and are not seriously in dispute. The precise outlines, the exact timing of each stage, and the shape of the continent at any single moment are model outputs, built from scattered and deformed evidence, and they carry the uncertainty that comes with that.

This is one detailed study rather than a closed case, and the fine print of the reconstruction will be revised as more data comes in.

What the reconstruction is good for

For van Hinsbergen’s group, the model is also a tool. Once the Mediterranean is reassembled, other features can be returned to where they began, including extinct volcanoes and ore deposits, which has a bearing on where those resources are found now. A buried continent, read backwards, turns out to be one way of working out how the surface above it was put together, and what got locked inside the mountains on the way.