Scientists from the British Geological Survey (BGS) working with Professor Bob Holdsworth from our Earth Sciences Department have been given access to cores drilled through the Great Glen Fault, the UK's largest fault zone.
The core was retrieved during investigations for a proposed hydro-storage project at Coire Glas, on the shores of Loch Lochy in the Scottish Highlands.
Why it matters?
At over 1,000 km long and some 40 km deep, the Great Glen Fault stretches from Ireland through Scotland to Norway.
The newly extracted rock core (which is the first of its kind from this fault) offers scientists a rare look deep beneath the Earth's surface.
The samples reveal how ancient tectonic shifts, mountain-building events, and geological forces shaped the fault over hundreds of millions of years.
The collection of such complete core sections from depth is challenging and costly. The rocks revealed from deep underground are poorly exposed at the surface as they have been hidden below glacial deposits or the waters of lochs.
By examining this core, researchers are uncovering how the fault behaved in the distant past and how fluids moving deep inside the earth might have changed the fault rock structure and mechanical behaviour.
A glimpse at earth's history
The findings are already helping scientists plan for the long term. The cores will be stored at BGS's National Geological Repository, ensuring they are preserved and available for future research.
For our geoscience community this reveals an exceptional natural laboratory, one that could shed light not only on how the Scottish Highlands formed but on how large fault systems worldwide behave including those in seismically active zones elsewhere.
More practically, understanding the deep structure and rock properties of the Great Glen Fault will inform the design of future energy projects where tunnelling is required.
