Eminent geologist and volcanologist;

Born: June 19, 1932; Died: February 2, 2013.

Professor Barry Dawson, who has died in Edinburgh aged 80, was a distinguished scientist and geologist. His work in east Africa studying the volcano Oldoinyo Lengai in Tanganyika brought him particular renown throughout his profession. That was further enhanced when he was appointed Professor of Geology at Edinburgh University, bringing to his teaching a natural ability and joy at imparting knowledge.

John Barry Dawson was born outside Leeds and read geology at Leeds University. Despite many years in Scotland he was to remain a proud Yorkshireman all his life. He studied for his PhD at the Centre for African Studies in Leeds (1956-1960), where he did research into kimberlite magmas and their xenoliths (a rock fragment which becomes enveloped in a larger rock).

He worked as a geologist for the Tanganyika Geological Survey, returning to the UK in 1964, where he was lecturer at St Andrews and later professor at the universities of Sheffield (from 1978) and then finally at Edinburgh (from 1989).

At all three appointments he was a much-respected lecturer – giving freely of his time, energy and knowledge to his students. He was acknowledged as an international authority in magmatism (the molten rock material under the Earth's crust) and he published various learned articles on the subject.

While at St Andrews, Prof Dawson collaborated with Joseph V Smith of Chicago University in analysing the composition of rocks and minerals brought to the Earth's surface. When they were sawing up the rock, the blade jammed and, quite fortuitously, Prof Dawson had found a layer of diamond. It proved a unique find and their subsequent research made geologists reassess various previously accepted theories.

It was his work in Tanzania for which Prof Dawson is particularly renowned amongst his colleagues. He first visited Oldoinyo Lengai –the only active carbonatite volcano on Earth – in the Tanzanian Rift Valley in the 1960s when he had worked as a geologist for the Tanganyika Geological Survey. In 1988 he revisited the volcano with a team of student geologists, having heard it was about to erupt. It proved a most exciting expedition with Prof Dawson mapping the active vents of the summit crater and gazing in amazement at the volcanic eruptions.

Professor David Pyle of Oxford University, who was a student on the field study, recalls that throughout Prof Dawson calmly delivered impromptu tutorials on the alkaline igneous rocks. At night he would enthusiastically continued his extempore lectures over a dram.

Although Prof Dawson retired in 1997 – when he was made Emeritus Professor of Geology at Edinburgh University – only two years ago he gave a keynote address at the department of earth sciences at Bristol University and three weeks ago completed a research paper with Dr Sally Gibson, now at Cambridge University and a former student of Prof Dawson.

"Barry remained alert and as bright as ever," she recalls. "He was a wonderful storyteller and loved walking the Scottish hills – he proudly bagged many Munros. He was a very special person."

In 1968 Prof Dawson won the Clough Memorial of the Edinburgh Geological Society and last year was awarded the Collins Medal of the Mineralogical Society.

His wife, Christine, predeceased him and he is survived by his son and two daughters.