Hergt is best known for her geochemical investigations of magmatic rocks although she has employed similar techniques in interdisciplinary projects including areas of archaeological and biological science.
[citation needed] Throughout her career, Hergt has retained a keen interest in extracting high quality geochemical data from rocks and minerals to solve problems in the geosciences.
[3] The dataset for the Tasmanian Dolerites, together with the extreme compositions of these rocks, provided the first opportunity to test competing hypotheses about source processes and constrain the origin of these magmas.
[8] Following her move to the University of Melbourne in 1994, Hergt's contributions have involved a wide range of international collaborators and graduate students, and have included investigations of continental flood basalts,[9] arc magmas,[10][11] granite formation,[12][13] ore deposits, the origin of kimberlites[14][15][16] and processes preserved in mantle xenoliths.
Hergt has also made important contributions in establishing innovative laboratory protocols[17][18][19][20][21][22] and has supported the development of Iolite data visualisation software since its inception.