Funny I just posted about it... the English name is “The Ice people”: https://en.m.wikipedia.org/wiki/The_Ice_People_(Barjavel_nov...

And yes a great sci-fi book, even so the civilization in question is just 900,000 years old not multi millions like the original article.

The book is called "Maps of the Ancient Sea Kings" - Charles H. Hapgood. (1966). Subtitle: Evidence of Advanced Civilization in the Ice Age.

https://www.goodreads.com/book/show/564770.Maps_of_the_Ancie...