He was a post-doctoral fellow in isotopic geochemistry until 1964 when he became a Scientific Staff Member .
Between 1964 and 1975 , Krogh worked at the Carnegie Institution in Washington , D.C.
Krogh was a post-doctoral Krogh in isotopic geochemistry until 1964 when Krogh became a Scientific Staff Member .
Between 1964 and 1975 , Krogh worked at the Carnegie Institution in Washington , D.C.