1865 June 37 A good mullock reef, 4 to 5 feet thick. Good prospects can be washed from this reef.
1875 (5th Sess. 5th Parl.) II. H.–3. 29 The reefs of the Carrick Range..are peculiar clayey ferruginous ‘mullock reefs’ or rather ‘quartz-mullock reefs’.
1965 G. J. Williams iii. 20/2 Mullock reef, a number of leaders traversing the mullock; collectively these may be worth working.