II II II II II - Geoscience Australia

Permian Alum Mountain Volcanics, in the Myall Syncline near Bulandelah (McIlveen,
1974). Analcite and bentonite, in altered tuffs in the Newcastle and Wollombi Coal
Measures respectively, may be of economic interest (Menzies, 1974). The fine-grained
sediments and tuffs in coal measures are often suitable for making bricks, tiles, and
earthenware pipes, an example being the exploitation of shales in the Tomago Coal
Measures near Newcastle. Refractory clays used in the manufacture of furnace-lining
bricks may also be found in such facies; particularly noteworthy are the flint clays in
the Skeletar Formation (Greta Coal Measures) and equivalents, derived from regolith
developed at the top of the underlying volcanics by deep weathering during a hiatus
in Permian 3 time. Permian limestone has been used on occasion, e.g. in Tasmania,
for agricultural purposes and making Portland cement.
Permian rocks have, of course, also been used for their physical properties, for
construction purposes such as building stone, concrete aggregate, road sub-base
course, fill for groynes and retaining walls, etc., wherever suitable outcrops occur close
to a need for these materials.
Throughout geological time there seems to have been a relation between glaciation
and subsequent phosphorite deposition (Cook & Shergold, 1986), and indeed globally
the Permian Period was a peak time of phosphogenesis (Cook & McElhinny, 1979).
Despite these favorable factors, the Australian Permian is not endowed with significant
phosphate deposits, the only reported occurrences being in the Liveringa and
Noonkanbah Formations of the Canning Basin (Ingram, 1973b), and concretions in the
Byro Group of the Carnarvon Basin (Cope, 1976). This deficiency is probably
attributable to the continent's high palmolatitude. Phosphorites are known to form
preferentially in low latitudes, and the richest Permian deposit, in the western USA, as
well as occurrences in the northern Caucasus, and probably Vietnam, were formed
within 30 0 of the palmo-equator. If, nevertheless, sizable deposits did accumulate in
the Australian Permian, the most favorable locations would have been in shallow
embayments extending inland from upwellings along the northwestern palmo-coast,
i.e. the Carnarvon, Canning, Bonaparte, and Arafura Basins. It is pertinent that the
Indian deposits of the Mussoorie region, and in the Himalayas north of Delhi, formed
at a similar palmolatitude.
DISCUSSION
From the stratigraphic columns three broad subdivisions of the Permian are apparent,
namely, Permian 1-3, in which non-marine facies dominate over marine ones,
especially in much of eastern Australia; Permian 4-5, with marine environments more
common, and in many basins separated from the first subdivision by a pronounced
hiatus; and Permian 6-7, when non-marine and paralic regimes were re-imposed in
most regions. The impression of non-marine dominance during Permian 1-3 is
deceptive, however, because the stratigraphic columns are biassed towards the
eastern half of the continent, where such conditions were more common. In terms of
the areas of marine lithotopes, the maps show a greater marine coverage in the
Asselian and Saknnarian than in the mid-Permian. Hence the broad, first-order marine
inundation curve starts from a maximum in the earliest Permian and declines through
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