Mark was born in Oak Park, Illinois, June 23, 1926. He was educated at the University of Illinois and Oklahoma State University from where he recieved his PhD in 1951. He went to the Oak Ridge National Laboratory in 1951 and spent sabbatical years at AERE Harwell, UK in 1964-65 and at KFA Julich in 1971-72. He also spent some time at the Max-Planck-Institute fur Plasmaphysik, Garching in 1983. He was trained as an experimental physical chemist but became interested in computer applications in about 1957-58. At that time he started collaborating with David K.Holmes and Ordean S. Oen on work that led to the discovery of channelling by computer simulation in 1962. This was quickly confirmed by groups working in Canada, the UK and Germany. His interest in computer simulation continued - particularly in sputtering, particle backscattering and radiation damage right up to his retiremnet in 1996.

His pioneering work in computer simulation led to the simulation program Marlowe which was much used and emulated through the 80s and well into the present time. His paper (with Ian M Torrens) on the use of the binary collision approximation in cascade simulations has attracted over 1,150 citations since it was published in 1974 and is still clocking up citations. His papers with Michael J. Norgett and Ordean S. Oen on displacement and ion reflection respectively have clocked up over 550 citations each.