MANCHESTER, UK – July 29, 2025 –
Scientists have unveiled the discovery of colossal, inverted geological formations beneath the North Sea, dubbed “Sinkites,” a finding that challenges fundamental principles of geology and carries significant implications for future carbon capture and storage (CCS) initiatives. These previously undocumented structures, some spanning several kilometers in width, appear to defy the conventional understanding of how sediment layers form.
The groundbreaking research, led by Professor Mads Huuse at The University of Manchester in collaboration with industry partners, utilized high-resolution 3D seismic imaging coupled with data and rock samples from hundreds of wells. Their findings, recently published in the journal Communications Earth & Environment, reveal vast sand bodies that have apparently sunk downwards, displacing older, lighter sediments that then “floated” to the top. This process, termed “stratigraphic inversion,” has been observed at smaller scales before, but the newly identified “sinkites” represent the largest known examples of this phenomenon.
“What we’ve found are structures where dense sand has sunk into lighter sediments that floated to the top of the sand, effectively flipping the conventional layers we’d expect to see and creating huge mounds beneath the sea,” explained Professor Huuse. The lighter, uplifted features displaced by the sinking sand have been termed “floatites” by the research team.
It is believed these “sinkites” formed millions of years ago, during the Late Miocene to Pliocene periods. Researchers hypothesize that earthquakes or sudden shifts in underground pressure may have caused the sand to temporarily liquefy, allowing it to penetrate through natural fractures in the seabed and sink into the underlying, more porous, but rigid bio-siliceous ooze.
The discovery has profound implications, particularly for the burgeoning field of carbon capture and storage (CCS). For CCS to be effective, large quantities of captured carbon dioxide must be injected and securely stored deep underground in suitable geological formations. The integrity of these reservoirs and the overlying “sealing” layers is paramount to prevent CO2 leakage.
“Understanding how these sinkites formed could significantly change how we assess underground reservoirs, sealing, and fluid migration — all of which are vital for carbon capture and storage,” Professor Huuse added. The unexpected movement and inversion of these layers could introduce new complexities and potential pathways for fluid migration, necessitating a careful re-evaluation of proposed storage sites in areas where such formations might exist.
The North Sea region is a key area for current and planned CCS projects, with many initiatives focusing on repurposing depleted oil and gas fields or utilizing deep saline aquifers for CO2 sequestration. The presence of “sinkites” means that geological models used to assess storage capacity and long-term containment integrity may need to be revised to account for these unusual subsurface structures.
While further research is needed to fully understand the extent and implications of “sinkites” globally, this discovery highlights the complex and often surprising nature of Earth’s subsurface. It underscores the critical importance of comprehensive geological surveys and ongoing scientific inquiry to ensure the safety and effectiveness of large-scale carbon storage solutions vital for climate change mitigation.
