[2][3][4][5] Marston was born in Bordertown, South Australia and educated at Unley District High School, Adelaide, where he met Mark Oliphant.

Marston was appointed a demonstrator in the university's department of physiology and biochemistry after a chance meeting with Professor Thorburn Robertson in 1922.

Experiments by Marston confirmed Dick Thomas's hypothesis that a cobalt deficiency was the primary cause of coast disease in sheep.

His project also tracked fallout across the continent by examining the thyroids of sheep and cattle as well as devices that filtered radioactive elements from air.

Later the results, which showed dramatic increases of certain radioactive elements after British Nuclear Tests, caused a further, controversial study where the bones of deceased people (especially children) were burnt to ash and then measured for Strontium-90.