Obituary by Mark Yonge (1961 F) as featured in The Guardian (14th February 2020)

My brother Charles Yonge, who has died aged 74, was a climber, explorer and caver who opened up many new routes and discovered caves all over the world. He also carried out numerous ascents in the Rocky Mountains in Canada.

Born in Chesterfield in Derbyshire, Charles was the son of Wg Cmdr John Yonge, an RAF pilot, and his wife, Enid (nee Blanch), who worked in surveillance for MI5. He was educated at Sutton Valence school in Kent and then at the University of Surrey, where he gained a degree in physics in 1967. He followed up with an MPhil in physics at the University of Sheffield, where his interest in climbing and caving was piqued.

Not long after he graduated his new passion nearly resulted in a catastrophe when, surprised by a freak rainstorm, he and a group of potholers were almost drowned by rising water in a deep cave near Settle in North Yorkshire.

In 1977 Charles emigrated to Canada, musing that “this is where the real mountains are”. Initially he lived in Ontario, and studied for a PhD in geochemistry and palaeoclimatology at McMaster University, Hamilton. There he met Pamela Burns, who was studying mathematics, and who later became a computer programmer/analyst. They married in 1981.

Charles opened a number of new climbs in Ontario on the Niagara Escarpment, including at Buffalo Crag and Mount Nemo. Later he settled with Pamela and their newly arrived triplets in Canmore, Alberta, in the Bow Valley of the Rocky Mountains. It was here that he made his name as a geological caving specialist, taking part in research projects in countries such as Cuba, Barbados, Mexico, the US and Papua New Guinea. During these visits he often explored, mapped and wrote about previously undiscovered caves.

In 1998 Charles set up a wild cave tour business in Canmore, with Pamela running the accounts. He lent his name to local climbing guidebooks and would frequently be seen clearing detritus from future rock climbing routes. He established climbs throughout the Bow Valley, many now regarded as classics.

One of his sidelines was dating moon rocks that had been brought back to Earth on the Apollo 11 mission of July 1969. During this work he found out that the International Astronomical Union was seeking names of well-known female authors for the physical features on the planet Venus. Because he was a direct descendant of the Victorian author Charlotte Mary Yonge, he put her forward, and a crater was named after her in 1994.

Towards the end of his life, which was affected by cancer, Charles published his book Understanding the Banff Hot Springs Through Karst Hydrogeology (2019). In the same year, he was awarded the Sir Christopher Ondaatje medal for exploration from the Royal Canadian Geographical Society.

He is survived by Pamela, their three children, Emma, Carolyn and Alexander, and his siblings, Charlotte, Jane and me.