U‐Pb zircon chronology of prograde Proterozoic events in the Central and Southern Provinces of the Arunta Block, central Australia

Abstract

A series of conventional and ion‐microprobe U‐Pb zircon ages broadly confirm the timing previously proposed from Rb‐Sr dating for three major tectonic episodes that fashioned the Arunta Block of central Australia. Ages of 1763+2 ‐1 Ma, 1760 ± 11 Ma and 1754 ± 9 Ma are derived for the Strangways Event, the oldest widespread tectonothermal activity to have affected the Central Tectonic Province. The two youngest values constrain the age of the second phase of folding within the Strangways Event in the central western part of the Central Tectonic Province to 1760–1750 Ma. The Southern Tectonic Province is demonstrably younger. Assuming that the analysed sample is representative, most of the currently exposed meta‐igneous rocks originally crystallized at 1660 ± 4 Ma in an event immediately preceding the Chewings phase of the Aileron Event, dated by Rb‐Sr at 1590 ± 70 Ma. This ca 1660 Ma succession of the Southern Arunta Province is younger than the youngest unit (Division 3) in the Reynolds Ranges region of t...