[4] After the end of the war, he entered Clare College, Cambridge, where he was influenced by John Edward Marr and Alfred Harker.

Along with Frederick Murray Trotter and others, he helped create new maps and memoirs of Brampton, Whitehaven, Gosforth, and Cockermouth districts of Cumberland.

When the Second World War began in 1939, Hollingworth joined a team tasked with updating and increasing geological knowledge of the Jurassic ironstones, particularly those in Northamptonshire such as Northampton Sand Formation.

These were particularly vital at that time as they served as the UK's chief domestic source of iron ore, which played a crucial part in steel production required by the war effort.

[4] Hollingworth returned to academia after the war ended, becoming the Yates-Goldsmid Professor of Geology at University College, London.

[4] In 1965, Eugen Friedrich Stumpfl and Andrew M. Clark named a sulfide mineral "Hollingworthite" of the Cobaltite group.