U-Th-Pb isotopic analyses have been made with an ion microprobe of 20–30 μm areas within zircons from gneisses adjacent to the Mount Narryer quartzite, Western Australia, in which detrital zircons up to 4200 Ma old have been found. The cores of the zircons yield protolith crystallization ages of 3678±6 Ma (95% confidence limits) for the Meeberrie banded monzogranite gneiss and 3381 ± 22 Ma for the Dugel syenogranite leucogneiss, in agreement with observed intrusive relationships. Zircons from inclusions of deformed leucogabbro and meta-anorthosite within the Dugel gneiss (formerly part of the Manfred layered igneous complex) are 3730±6 Ma old. The remnants of the Manfred Complex are therefore the oldest rocks currently known on the Australian continent. Analyses of discrete post-magmatic grains and of overgrowths on older grains indicate an episode of subsolidus zircon growth in the region at 3296±4 Ma, which is interpreted as a time of local metamorphism of the gneisses. Subsequently, the zircons have been rounded and embayed and have lost radiogenic Pb in both ancient and recent times. All the zircon ages determined in this study are within the age range for detrital zircons in the Mount Narryer quartzite; it is therefore possible that these felsic gneisses and anorthositic rocks were a local source for some of the sedimentary material. However, the lateral extent of this early Archaean terrain and the source rocks for the rare 4100–4200 Ma old zircons in the metasediments are yet to be determined.