Jurassic Pink Granite Boulders Reveal Subterranean Geological Giant Beneath Antarctica’s Pine Island Glacier

Strange pink rocks on Antarctic peaks lead BAS scientists to a 100km-wide hidden granite mass. Learn how this solves a 70-million-year-old mystery.

By: AXL Media

Published: Mar 19, 2026, 11:49 AM EDT

Source: Information for this report was sourced from British Antarctic Survey (BAS)

Solving a Decades Old Polar Geological Mystery

The presence of bright pink granite boulders scattered across the dark, volcanic ridges of the Hudson Mountains has long presented a geographical anomaly for polar researchers. These stones appeared entirely out of place against the local basaltic landscape, sparking a multi-decade investigation into their origins. A new study led by the British Antarctic Survey (BAS) has finally traced these stray rocks to a gargantuan, hidden mass of granite buried nearly seven kilometers beneath the Pine Island Glacier, providing a rare glimpse into the subglacial architecture of the Antarctic continent.

Radioactive Dating Traces Origins to the Jurassic Period

To determine the age and source of the mysterious pink stones, the research team employed advanced geochronological techniques, measuring the radioactive decay of elements trapped within microscopic mineral crystals. The analysis confirmed that the granite formed approximately 175 million years ago during the Jurassic period. This data point was essential for the team to begin searching for a matching geological "parent" structure within the region, eventually leading them to look beneath the thick ice sheets that currently mask the continent's bedrock.

Airborne Gravity Surveys Map the Subsurface Giant

Because the source of the granite remains inaccessible under kilometers of ice, scientists utilized Twin Otter aircraft equipped with highly sensitive gravity sensors to peer beneath the surface. These airborne surveys detected a massive gravitational signal consistent with a granite body stretching 100 kilometers in width. By correlating the chemical signature of the surface boulders with this newly mapped underground giant, the researchers confirmed that the stones were plucked from the base of the glacier and transported uphill during an era when the ice sheet was significantly thicker than it is today.