Admitted into the Society of Foreign Missions of Paris and ordained in 1948, he was sent to Hanoi (Vietnam) in 1951[1] as professor at the Petit Séminaire.
He founded the Department of Geology of the University of Huê (ancient imperial capital) and supported post-graduate students at the Faculty of Sciences of Saigon.
[10] He also contributed to developing pilot studies in order to build up dams on different rivers (La Nga, Dông Nai ...) and to explore heavy minerals in dunes of sand, along the eastern coast, and bauxite on basaltic plateaus.
On fieldworks, he discovered a prehistoric site at Phuoc Tân (on the route to Bà Ria) and unearthed many others (Ngai Thang, Cù lao Rùa, ...).
[18] Father Fontaine succeeded Mr André Bonnet,[18] another French geologist, and spent many months each year in Asia.