SEISMIC activity 55 million years ago rendered the geology of the UK unsuitable for fracking, according to a leading expert, who also said the potential for the new energy source has been “overhyped”.

Professor John Underhill, Chair of Exploration Geoscience and chief scientist at Heriot-Watt University in Edinburgh, suggested the UK was “55 million years too late” for the gas extraction technique to work.

Fracking — hydraulic fracturing — involves drilling into the earth and injecting liquid into the rock at high pressure, forcing it to fracture and gas deposits to escape.

However, Underhill said shale gas reservoirs had been damaged by seismic activity millions of years ago, when the Iceland hotspot (volcanic activity that helped create the island) started to form, causing “igneous intrusions” such as Arran, Mull and Skye. The Atlantic Ocean also started to open at that point, causing uplift and tilt.

“The British Isles were moving east and Greenland was moving west but the British Isles had nowhere to go because Europe was in the way and so it also buckled,” he said.

“Three effects, uplift, tilt and buckle, and the key thing for the shale gas plays (formations) is that all are affected by one or more of those processes and become deformed.”

Opponents claim fracking will harm the environment, but supporters say it is a beneficial source of energy.

“Both sides assume that the geology is a ‘slam dunk’ and it will work if exploration drilling goes ahead,” said Underhill. “Public support for fracking is at an all-time low of 17 per cent, based in the main on environmental concerns, but the science shows that our country’s geology is simply unsuitable for shale oil and gas production.

“The implication that because fracking works in the US, it must also work here is wrong. The key difference from the US shale plays is that they are all formed between the Appalachians and the Rockies in the continental interior, not on the plate margin.

“For hydraulic fracturing to be successful, a number of geological criteria must be met. The source rock should have a high organic content, a good thickness, be sufficiently porous and have the right mineralogy. The organic matter must have been buried to a sufficient depth and heated to the degree that the source rock produces substantial amounts of gas or oil. However, in locations where fulfilment of some of the criteria have led to large potential deposits, uplift and the faulted structure of the basins are detrimental to its ultimate recovery.

“In the US the plays that work for shale gas are at their greatest depths of burial. In the UK because of his uplift — around two to three kilometres in the Outer Hebrides, reducing to a kilometre by the time you get to Inverness, to zero off the east coast of Scotland.

“What that’s done is to cause the oldest rocks in the UK to be exposed in Lewis and Harris and the youngest in south east England. All three basins that are the focus of shale gas extraction potential (West Lothian, Bowland in Lancashire and Weald in southern England) have been affected in some way by the uplift, tilt or buckling.”

Underhill, who has been involved in geoscience for 25 years, added that the only question addressed to date was how large the UK’s shale resource is.

“The inherent complexity of the sedimentary basins has not been fully appreciated or articulated and, as a result, the opportunity has been overhyped,” he said.

“The debate is polarised between the environment, social licence to operate and oil and gas practitioners. The bedrock of the argument is geology, and I have a responsibility to say these basins have been uplifted and ask what impact that has.”

His analysis was welcomed by Mary Church, head of campaigns at Friends of the Earth Scotland (FoES), who said it added to the already overwhelming case against fracking here: “He is not the first geologist to point out serious flaws in the case the industry makes for pursuing shale gas, and no doubt he won’t be the last. We have long highlighted the misleading use of US shale gas economics by industry players like Ineos to make a case for fracking in Scotland.

“However, even if Scotland’s geology presented ideal conditions for shale gas extraction, the case against fracking is still very clear. Fracking presents a whole host of risks to people’s health and our local environment, while in the context of irreversible climate change, going after a new source of fossil fuels is quite literally the last thing we should be doing.”