II II II II II - Geoscience Australia

ocks at all of Permian 4 age, could be a reflection of the same event. All this
coincided with folding and serpentinite emplacement east of the Bowen Basin (Malone
& others, 1969), both of which may have been caused by the docking of the Curtis
terrane.
PERMIAN 5: EARLY KAZANIAN (UFIMIAN) (-256-258 Ma)
The incoming of Fauna IV, after the hiatus in eastern Australia, marks the beginning
of the Late Permian and the base of the next time slice. This interval, though of less
than 2 m.y. duration, is distinguished by an important marine transgression in many
basins.
Most notable is the establishment of a seaway along the full length of the Sydney -
Bowen trough, isolating the New England - Yarrol highlands from the mainland. The
continuity of this seaway across the New South Wales - Queensland border has been
verified by recent drilling in the northern Gunnedah Basin (M. Hill, GSNSW, pers.
comm. 1986). The northwestern margin area of the Bowen Basin was claimed by a
Permian sea for the first time, but on the Springsure Shelf to the south, a fluvial facies
prevailed. The dying stages of the submarine Rookwood volcanism were evident west
of Rockhampton. Ice-borne erratics are common in the Sydney and Gunnedah
Basins, but the souce of the ice is speculative; much of the ice was probably
seasonal, though remnant glaciers debouching from the adjacent mountains cannot
be discounted. The small Gloucester Basin at the southern tip of the New England
land mass experienced paralic conditions.
Felsic volcanism began afresh in the Drake district of New England, but apparently
nowhere else in the province, even though there may have been other magmatic
activity, such as near Armidale, where the Dummy Creek Conglomerate has been
interpreted as infilling rim synclines formed as a result of intruding igneous diapirs
(Korsch, 1977). The eastern sea, which had an ennbayment southwest of Warwick,
was inhabited by a shelfal fauna including corals, and uninterrupted deposition was
maintained for the South Curra Limestone in the Gympie Terrane.
In Tasmania, the transgression reached its maximum extent, with only the northeast
and northwest corners of the state, and some islands in the east, remaining above sea
level. A sea level drop at the close of the time span led to the formation of the Risdon
Sandstone offshore barrier bar facies in the Hobart region (Banks & Clarke, 1987).
Transgression also continued in the Bonaparte and Carnarvon Basins. The product
of sedimentation in the Bonaparte was the bryozoal biomicrite at the top of the Fossil
Head Formation. Most of the Carnarvon Basin was characterized by a broad sandy
shelf with a very low palmoslope (Moore & others, 1980b), but paralic fades formed
along the shoreline, especially along the northern margin of the basin where debris
was shed into the sea from the scarp of the active Sholl Island Fault (Kopsen &
McGann, 1985; Bentley, 1988).
The Canning Basin by contrast was dominated by tectonic emergence of the southern
and central portions, which were to last as dry land until the Late Jurassic. But the
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