Chapter 3.6 The Narryer Terrane, Western Australia: A Review

Abstract

Publisher Summary This chapter presents a review of the Narryer terrane, Western Australia. The Narryer Terrane occupies an area of ∼30,000 km2 in the northwestern corner of the Archean Yilgarn Craton of Western Australia. It is one of the earliest crustal terranes on the Earth, containing rocks with U-Pb zircon ages ranging up to 3730 Ma, the oldest known rocks in Australia, and detrital zircons up to 4404 Ma, the oldest terrestrial material on the Earth. Initial geochronological investigations on granitic gneisses in the vicinity of Mt. Narryer, using Rb-Sr whole-rock techniques, established an age of 3348 ± 43 Ma using multicomponent samples. An initial investigation of the Mt. Narryer area commenced using the SHRIMP ion microprobe, including not only a study of the ancient gneisses, but also of the detrital zircon population in the granulite facies quartzites and conglomerates. This led to the exciting discovery of four detrital zircon cores with ages ranging from 4110 to 4190 Ma, the oldest crustal remnants identified on the Earth at that time. The Jack Hills metasedimentary belt lies ∼60 km NE of Mt. Narryer and is approximately 90 km long with a pronounced sigmoidal curvature, typical of a dextral shear zone. It is found that the margins of the belt are sheared and have steep dips, indicating that the belt itself is also steeply dipping.