II II II II II - Geoscience Australia

The marine region of eastern New England shallowed to become a carbonate-clastic
province, as indicated by units such as the Yessabah Limestone and Warbro
Formations (Hastings Block), and the Kimbriki Formation and Cedar Party Limestone
(Manning district). The Nambucca beds and western equivalents still suggest deep
water, but age control for them is poor, and they may be older than this time slice.
Water depths over the Gympie Terrane are uncertain; the Highbury Volcanics were
still erupting.
The northern Perth Basin early in the interval received a richly fossiliferous, shallow
marine carbonate-lutite sequence (the Fossil Cliff Member), followed by a shallow
marine sandstone which may have been partly littoral in origin (Playford & others,
1976). The siliciclastics coarsen towards the Darling and Urella Faults, perhaps being
a tectonic signature of activity on these structures during or before the emplacement
of these sediments. At the close of the interval, the fluvial facies of the Irwin River Coal
Measures extended across the region following a marine regression.
The eastern Carnarvon Basin experienced a series of diverse events during Permian
3, recording an interplay of marine and paralic lithotopes due to fluctuating shorelines.
At first, low clastic influx on a wide shelf gave rise to the highly fossiliferous carbonatelutite
associations of the Carrandibby and Callytharra Formations (Layering, 1985).
After a withdrawal of the sea exposed the southeastern basin to a period of karstforming
subaerial weathering, renewed sea level rise and transgression set the stage
for the outbuilding of a large delta complex (the Wooramel Group). This delta was
initially sand-rich, but after inundation by further sea level rise, a mud-prone deltaic
progradation was established, only to be drowned in turn as marine shelf
sedimentation was finally restored. The Wooramel delta complex had more than twice
the area of the Mississippi delta according to Lavering's map reconstruction, and must
have been fed by a comparably large drainage system. The catchment area probably
extended to the central Australian highlands, and may have drained part of Antarctica
as well. Offshore from the delta, shelf conditions prevailed.
The Canning Basin began the interval with an erosional hiatus, caused either by uplift
(Crowe & others, 1983), or by a eustatic sea level low stand. Most of the basin was
then transgressed, resulting in a widspread nearshore to very shallow marine,
dominantly sandy sequence (the Poole Sandstone). Its basal Nura Nura Member in
the northwest tends to be calcareous and coquinitic, however, and preserves a faunal
assemblage which lived in warm to temperate open seas (Foreman & Wales, 1981).
A contemporaneous fauna in the south of the basin (Towner & others, 1983) implies
similar conditions there. The northern margin differed again, in that a migrating barrier
bar and lagoonal zone was constructed between the sea and an apron of coalescing
fan deltas at the distal end of braided fluvial systems draining the Kimberley highlands
to the north.
A prograding shoreline of sandy deltas with minor coal (lower Sugarloaf Formation)
was constructed along the eastern Bonaparte Basin (Dickins & others, 1972). Most
of the basin continued to be shallow marine, receiving fine, carbonaceous, prodeltaic
clastics, and some limestone (Laws & Brown, 1976). Hughes (1978) shows a
basement high near Newby 1 on which no Permian was detected by seimic work; this
may have formed a small erosional area throughout most of the Permian. Undrilled
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