Scottish ministers are being urged to save the threatened subject of geology at Higher after a significant increase in the number of pupils sitting the exam.

In 2012, just 17 pupils sat the subject - set to be axed by the Scottish Qualifications Authority (SQA) in two years time - but this year numbers rose to 64.

Although the figure is still low, other subjects such as Chinese Languages also have a small uptake, but are considered too important to scrap.

Academics and scientists believe pupils have a natural interest in the subject and should be made aware of the critical role geologists play in key industries vital to the future prosperity of Scotland, such as gas and oil.

Mike Robinson, chief executive of the Royal Scottish Geographical Society, said it was "remarkable" numbers were increasing when the subject was being run down and no new teachers had been trained since 1985.

"This growth is great, but it will be very difficult to sustain in 2014 with the continued attitude of SQA and the apparent lack of support for earth science in some sectors of government," he said.

"It reinforces our strong belief that there is a very real appetite for a course at Higher and the SQA has a real opportunity to distil this enthusiasm and grassroots demand."

Geologist and television presenter Professor Iain Stewart, who fronted the BBC's BAFTA-nominated "Earth: The Power of the Planet" backed the call.

"It is wrong for the SQA to use a blip in the figures to justify closing the Higher and we need to look again at the curriculum to see how the subject can be promoted rather than run down," he said.

There was also concern from Dr Ruth Robinson, senior lecturer in the University of St Andrews' School of Geography and Geosciences, who has been leading an outreach project visiting schools across Scotland to promote the subject.

"Pupils have a natural interest in the rocks beneath their feet and the minerals and fossils that can be found there," she said. "We have been met with tremendous enthusiasm and we now need the Scottish Government and the SQA to build on that."

Glen Cayley, Upstream Director or Shell UK & Ireland, stressed the importance of geologists to the oil and gas industry.

"Geologists are very much at the centre of the search for vital oil and gas reserves," he said.

However, the SQA said, despite the increase at Higher, overall geology entries were down and there was not the required infrastructure to support it as a distinct subject.

A spokesman said: "We recognise the importance of earth sciences for Scotland. But, as far as we are aware, no UK university currently asks for geology as an entry requirement onto a geology course.

"Aspects of geology are included in the new chemistry, physics, geography, science and environmental science courses.

"We are keen to look at innovative ways of developing qualifications and SQA has met geology specialists with a view to determining demand for an earth science qualification."