High-precision U-series dating of very young cyclone-transported coral reef blocks from Heron and Wistari reefs, southern Great Barrier Reef, Australia

Numerous high-energy-transported coral reef blocks occur on the outer reef flats of Heron and Wistari reefs at the southern end of the Great Barrier Reef. In a pilot study, five samples from Heron and one from Wistari were collected for high-precision U-series dating by thermal ionization mass spectrometry. Five of the six dated corals yield U-series dates that suggest these corals were killed and transported during the last century. Without precise knowledge of cyclone impacts in the area, it is not possible to unequivocally link these reef blocks to specific cyclones. Nevertheless, this pilot study demonstrates that cyclone-transported coral reef blocks over the past 300 years can be precisely dated to an age uncertainty of ±1–4 years. This opens up the opportunity for high-age-resolution reconstruction of cyclone history and high-precision assessment of the trend and frequency of cyclone occurrences over the past millennium, as well as for a better understanding of anthropogenic impact on cyclone activity.