The concept that granitoids of the Lachlan Fold Belt in southeast Australia, are derived from either igneous or sedimentary source rocks (I- or S-type), can be extended to volcanic rocks of the same age. Three suites of late Silurian S-type volcanics are described, two of which can be matched quite closely with plutonic equivalents. A large part of the Paleozoic continental margin volcanic activity in southeast Australia consisted of the magmatic recycling of old metasedimentary crust, probably of late Proterozoic age. The three valcanic suites are moderately to strongly peraluminous, with the corresponding presence of Al-rich minerals. Variation within the volcanic suites is ascribed chiefly to progressive removal of restite, or source material residual from partial melting. The most mafic suite, the Hawkins Suite, contains plagioclase, cordierite, orthopyroxene, biotite and quartz as restite components, with less abundant almandine. These rocks are chemically equivalent to mafic biotite-rich and cordierite-bearing granitoids from parts of the Berridale and Murrumbidgee Batholiths, Garnet is absent from the Goobarragandra Suite volcanics, which are a little more felsic and close in composition to granitoids of the Young and Maragle Batholiths. The S-type character of the Laidlaw Suite is less pronounced although a sedimentary source seems to be established. Such a source would be less mature than those for the other two volcanic suites. The Laidlaw Suite resembles, but cannot be closely identified with, felsic S-type granitoids of the Murrumbidgee and Berridale Batholiths. Low-grade regional metamorphism in most of the volcanic rocks has resulted in much mineralogical alteration and mobility of alkali and alkaline earth elements. Despite this alteration, unaltered rocks are present in all three suites. Compositional data for the phenocryst phases within the unaltered rocks has allowed estimation of some intensive parameters. Hawkins Suite volcanics were extruded directly from their source region and preserve phenocryst equilibria established at 5--6 kbar at 800 ¿C. The Laidlaw and Goobarragandra Suites reequilibrated at lower pressures than their source before extrusion. The Laidlaw Wuite reequilibrated at estimated temperatures of 725¿--730 ¿C, fO2 of 10-15.5 to 10-14 bars, and f(H2O) of 2 to 2.5 kbar. Differing mineral compositions in the three suites are related to differing source rock compositions and oxygen fugacities. Relative biotite and orthopyroxene mg is possibly pressure dependent.