Chemical analyses of mafic to felsic metavolcanic rocks below and within fault slices of the Peel Fault System at Glenrock Station, N.S.W., show that several magmatic suites are present. The mafic metavolcanic rocks intercalated with volcanogenic sediments and calc‐alkaline volcanic rocks of the Tamworth Group are island arc tholeiites. Dolerites that intrude the sediments have tholeiitic or transitional characteristics. Ordovician‐Devonian(?) sediments, lithologically similar to the Woolomin Beds, contain island arc and intraplate‐intrusive rocks, and ocean floor, tholeiitic basalt. A sequence thrust over these beds contains calc‐alkaline volcanic rocks and mafic metavolcanic rocks of island arc character, which are poorer in Ti than the Tamworth Group mafic rocks. The source area for some of the volcanic rocks in the Tamworth Group may be to the east of the Peel Fault System.