A Cenozoic Great Barrier Reef on Australia's North West shelf

Dating the Northwest Shelf of Australia Since the Pliocene

“…However, integration of seismic data with correlated NGR and biostratigraphical data provides regularly distributed control points that allow for accurate tracing of these horizons, even across uncertain sections. This integration between the NGR, biostratigraphy and seismic data increased the accuracy and absolute age determination of previously published seismic horizons (H6 and H7; Belde et al, 2017;McCaffrey et al, 2020) across the shelf between IODP 356 sites U1462 and U1464. The independent benthic foraminiferal age model constrains the age of seismic reflectors H6 at ∼6.2 Ma (408 m WMSF in U1463; previously dated at 5.5 Ma [McCaffrey et al, 2020]) and H7 at 1.89 Ma (191 m WMSF in U1463; previously dated at 3-2.5 Ma [McCaffrey et al, 2020]) (Belde et al, 2017;McCaffrey et al, 2020;Rosleff-Soerensen et al, 2012).…”

“…(2017) and McCaffrey et al. (2020) with updated ages for H6 and H7. The Base Cenozoic reflector is used in the industry as a consistent standard reflector for the NWS.…”

“…Seismic profile perpendicular to the seismic profile inFigure 6anchored at the location of IODP Site U1463 showing the continuation of the main reflectors downslope, Miocene reefal carbonates previously identified byMcCaffrey et al (2020), and the newly appointed Picard slide covering the underlying sediment sequence. The NGR record of IODP Site U1463 is shown for comparison with the seismics including the ages for reflectors H6 and H7 and specific depth markers as indicated inFigure 4.…”

“…Seismic correlation and identification of characteristic features were performed using the IHS Markit Kingdom software using standard criteria for identification (Mitchum Jr. et al, 1977). The characteristic horizons H5 (Tortonian), H6 (Base Pliocene), and H7 (Base Pleistocene) were used as baseline to correlate the different seismic profiles (Belde et al, 2017;McCaffrey et al, 2020).…”

“…Alongshore seismic profile from IODP Site U1462 to IODP Site U1464 showing that the main seismic reflectors during the late Neogene can be followed along the NWS. The reflectors Base Cenozoic and H1-H7 are based onBelde et al (2017) andMcCaffrey et al (2020) with updated ages for H6 and H7. The Base Cenozoic reflector is used in the industry as a consistent standard reflector for the NWS.…”