In the depths of the North Sea, the marine background is behaving unexpectedly.
A team of scientists at the University of Manchester, UK, discovered hundreds of huge mountains of sand, some with several kilometers long, which “contradict geological principles fundamental ”.
According to one from the university, these hills accumulate about structures known as sinkitesresult of a process called stratigraphic reversalnever before observed in such a large number.
The discovery was presented in a recently published Communications Earth & Environment.
“This discovery reveals a geological process that we had never seen on this scale,” says the geophysic Mads huuseresearcher at the University of Manchester and co-author of the study.
“What we found are structures where dense sand sank in lighter sediments, which floated to the sand, reversing in practice The conventional layers we would expect to observe and create huge mountains at the bottom of the sea, ”he explains.
The geological layers tend to follow a coherent order With the linear progression of time: the oldest are at the base of formation and gradually become more recent as they approach the surface, according to the deposition.
A stratigraphic inversion, or inverted stratigraphyoccurs when more recent layers come down and the oldest rise to the top of training. This can happen in many ways, from landslides from rock to tectonic movements.
Huuse and colleague, the geophysical Jan Erik Rudjordfrom the Norwegian oil company Aker BP, identified the sinkites At the bottom of the North Sea through detailed seismic data.
When the Acoustic waves cross the earthpropagate and reflect differently depending on the density of the materials. Scientists then analyze these seismic records to map the different types of rock crossed by the waves.
In these data, Huuse and Rudjord concluded that large parts of the North Sea bottom seemed to be the oppositewith more recent layers of sanded sand under older layers.
These latest layers They are denser and heavier than the softer and lightweight material underneath. Over time, they sink, shifting the older and older material and forcing him to rise, where he began to sit on the denser Sinkite.
The investigators baptized the porous rafts resulting from floatites.
It is believed that this process occurred around the transition between myocenic and the plyecene, about 5.3 million years ago. The oldest material consisted of a light, rigid and porous layer, composed mainly by microscopic marine fossils, which deposited a heavier layer.
Disturbances like sismos may have fragmented the upper layer in sand, which sank, changing places with the floatites. Over the next few years, marine sediments have been covering the entire structure, forming the wavy background that is now in that area.
“This investigation shows how fluids and sediments can move in the earth’s crust in unexpected ways. Understanding how these sinkites formed can significantly change how we evaluate underground reservoirs, sealing and fluid migration-crucial factors for carbon capture and storage,” says Huuse.
“As with many scientific discoveries, There are many skeptical voicesbut also many that support this new model. Time and more research will say to what extent it can be applied, ”concludes the researcher.
