The significance of E–W structural trends for the Alice Springs Orogeny in the Charters Towers Province, North Queensland

E–W structural and igneous trends in the Charters Towers Province are highly anomalous within the overall N–S trending Tasman orogen of eastern Australia and resulted from a sequence of N–S shortening events. A succession of ~ E–W trending FIAs (Foliation Intersection/Inflexion Axis preserved within porphyroblasts) dated at 474.7 ± 7.2, 413 ± 13 and 381.1 ± 8.1 Ma correspond with adjacent granite crystallization ages and E–W trending FIA ages in the Greenvale Province to the NW. The magnetic anomaly map of Australia reveals that this E–W trending portion of the Tasman orogen links with and truncates several earlier formed orogens. The E–W trend of the Charters Towers Province resulted from overprinting of early Palaeozoic N–S trending structures in the Tasman Orogen by younger E–W ones during the Alice Springs Orogeny (450–300 Ma) resolving the E–W pluton shape and distribution of Cambrian to Devonian magmatic activity plus the truncational nature of aeromagnetic data from Central Australia to the East coast.

► Tectonic structures revealed by aeromagnetic truncational trends
► Synchronous pluton emplacement and FIA development
► Successive N–S shortening events previously not recognized in NE Australia
► Correlation between deformation from Central to Eastern Australia