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Through new palynological and chronostratigraphic (40Ar/39Ar dating) analyses we constrain the ages of important Australian Eastern Highland macrofloral sites. The Cambalong Creek site is late Paleocene (Selandian-Thanetian), with an age range of ∼ 57.3–59.8 Ma as inferred from palynostratigraphy (Proteacidites angulatus Subzone of the Lower Lygistepollenites balmei Zone). The Brandy Creek, Hotham Heights and Mount Buller sites are middle Eocene (Lutetian-Bartonian), with a minimum age of 39.58 ± 0.30 Ma, as inferred from 40Ar/39Ar analyses of overlying basalts, and a maximum age of ∼ 44 Ma inferred from palynostratigraphy (Lower Nothofagidites asperus Zone). The Kiandra Diggings site is early Miocene (Aquitanian), with a minimum age of 21.67 ± 0.26 Ma as inferred from 40Ar/39Ar dating and a maximum age of 23.03 Ma inferred from palynostratigraphy (Middle Proteacidites tuberculatus Zone). In the context of their revised ages, the recovered macrofloras suggest that subtropical climates prevailed during the late Paleocene (Cambalong Creek) and middle Eocene (Brandy Creek and Hotham Heights), whereas temperate climates existed during the early Miocene (Kiandra Diggings). For the middle Eocene sites, there is no discernible difference in paleotemperature estimates between lowland and highland sites, suggesting relatively low (< 550 m) paleoelevations for the present-day highland sites during the middle Eocene. This suggests that most of the present-day elevation (> 1400 m) was produced by post-middle Eocene uplift. • Ages of important Australian Eastern Highland macrofloral sites constrained. • Ages inferred through palynostratigraphy and 40Ar/39Ar analyses. • Subtropical climates in SE Australia during the late Paleocene and middle Eocene. • Similar temperature estimates for lowland and highland Eocene sites. • Present-day elevation (> 1400 m) produced by post-middle Eocene uplift. [ABSTRACT FROM AUTHOR]

The Eocene–Miocene succession of the onshore Gippsland Basin is host to some of the world's thickest coal seams. Here, we document well-preserved Paleocene coals from the offshore Gippsland Basin. The Paleocene sediments in the basin consist of three stacked coastal units, known informally here as T8, T7 and T6, in order of decreasing age. Each unit consists of, from seaward to landward, a sediment starved marine facies, a sand-rich, wave-dominated shoreface facies, lower coastal plain tidal and peatland facies, and upper coastal plain sandy, fluvial facies. Seismic amplitude extractions reveal unprecedented details of the peatland palaeogeography. The early Paleocene T8 palaeogeography reveals a wave-dominated, sandy strandplain seaward of a >1000 km2 lower coastal plain peatland. The peats extend inland to ~35 km from the paleocoastline and are dissected by a series of meandering and anastomosing channel systems. This geometry is remarkably similar to the modern tropical peatlands of the Rajang Delta in Sarawak, where forested domed peats have formed over tidal and shoreline sediments. The Paleocene coals of the Gippsland Basin have likely formed in a very similar stratigraphic setting and provide a large-scale ancient example of lower coastal plain coal deposition. • The Paleocene in the Gippsland Basin consists of three prograding shoreface units. • The dominant coal-forming environment is lower coastal plain. • Peats accumulated on elevated domes. • The shoreface is wave dominated with strandlines. [ABSTRACT FROM AUTHOR]