Mid-Late Tertiary Deep-Water Temperate Carbonate Deposition, Offshore Gippsland Basin, Southeastern Australia

Petrogenesis of diachronous mixed siliciclastic‐carbonate megafacies in the cool‐water Oligocene Tikorangi formation, Taranaki Basin, New Zealand

“…In comparison, hemipelagic muds in the Gippsland case accumulated at rates of < 10-80 m/m.y. (Bernecker et al 1997), values more consistent with calculated rates for Tikorangi Formation at Maui-1 well of only 7 m/m.y. …”

“…The higher rate is similar to that of c. 220 m/m.y. for fine-grained siliciclastic-rich turbidites reported by Bernecker et al (1997) for Tertiary deep-water mixed shelf-slope temperate carbonate of the Seaspray Group in the Gippsland Basin, southeastern Australia, and provides supportive evidence for a mass-emplacement origin for much of the foredeep megafacies. In comparison, hemipelagic muds in the Gippsland case accumulated at rates of < 10-80 m/m.y.…”

“…The occurrence and importance of carbonate mass redeposition events in the cool-water setting, whether solely or truly highstand or not, is certainly worthy of specific mention alone. Bernecker et al (1997) document for the Oligocene-Miocene Seaspray Group, Gippsland Basin, southeastern Australia, that sediments are fine-grained siliciclastic-rich calc-turbidites and bioclastic wackestone and packstone, deposited on the slope. The exact nature of the turbidite flows in southeastern Australia is difficult to assess, their overall fine-grained character suggesting the carbonate materials were transported in low-to medium-concentration turbidity currents.…”

Pliocene – Pleistocene history of the Gippsland Basin outer shelf and canyon heads, southeast Australia

“…Quaternary shelf sediments have aggraded to a maximum of 120 -150 m ( Figure 6) at an averaged compacted deposition rate of 62 -77 mm/ky, which is comparable to rates estimated by Holdgate and Gallagher (1997) and Bernecker et al (1997) for the Tertiary Gippsland shelf. Yet, the shelf-break has prograded some 10 km since the latest Pliocene (45 m/ky).…”

“…Shepard (1981) speculated that modern submarine canyons were likely to be the product of a number of processes and, of more importance, he suggested that the long-time persistence of such processes was of great importance in canyon formation. Major canyon structures in the carbonate Seaspray Group first develop during the Oligocene (Conolly 1968) and Middle Miocene (Maung & Cadman 1992;Bernecker et al 1997;Feary & Loutit 1998;Holdgate et al 2000). Yet, it has been suggested that the Bass Canyon (sensu stricto) may have structural origins that relate to the breakup of Gondwana, where it may have acted as a conduit for clastic sediments in the Late Cretaceous (Hill et al 1998 slope-confined canyons, may span considerable lengths of time in the geological record, responding to, and preserving, long-term oceanographic conditions.…”