II II II II II - Geoscience Australia

sequences underlying parts of the Surat and Eromanga Basins are source rocks for
hydrocarbon plays in the younger cover. In addition, Permian igneous rocks have
yielded gold, silver, copper, lead, zinc, tin, wolfram, bismuth, molybdenum, and other
metals. From a scientific viewpoint, the climate of Permian Australia, the Early Permian
glaciation, and the widespread coal accumulation of the Period, have always claimed
major attention internationally. Most of these features and resources are directly
related to the Permian palmogeography. Although it is not the intention of these maps
to examine in detail the palmogeographic distribution of the mineral and energy
resources, the maps obviously provide an opportunity for carrying out such an
evaluation, and will be very useful as the basis for exploration models.
CORRELATIONS
The primary biostratigraphic scales used for the main Permian correlation chart are the
palynological stages of Price (1983), and the Western Australian palynological stages
of Balme (in Kemp & others, 1977). Price & others (1985) have since revised the
former scale, but their changes mostly involve renumbering of the stages, and have
not yet been used extensively by others (Fig. 1); other changes are the subdivision
of upper Stage 4b into two zones, and the merging of upper Stages 5b and 5c
because the putative "index" fossil Microreticulatisporites bitriangularis is now known
to make its first appearance at different times in various basins.
A plethora of faunal zones, often competing, have been set up for various local
regions and different faunal groups, and many conflicting correlation schemes have
been published for these zones and the stratigraphy. The disageennents among faunal
palaeontologists are such that it was decided to adopt palynological stages as the
primary biostratigraphic reference for the main correlation chart, because these are
less controversial and seem to be more reliable; they also offer a wider coverage
across the continent than the more parochial faunal zones. Palynology does have its
own limitations, however, not the least of these being that in some areas
palynomorphs are not preserved, or lack sufficient diversity. In such areas, faunal
zones can have an important role. A faunal zones chart, explained in detail by Brakel
(in preparation), relates the faunas and the various interpretations of different workers
to the palynological stages. The zonations applicable to various regions are those of
Dickins (1963) and Archbold (1982) for Western Australia, Palmieri (1983), Dickins
(1964, 1968), Dear (1972), and McClung (1981a) for the Bowen Basin, Runnegar
(1969) for the Sydney Basin, Clarke & Banks (1975) and Clarke & Farmer (1976) for
the Tasmania Basin, and Runnegar & McClung (1975) and Runnegar & Campbell
(1976) for eastern Australia generally.
Isotopic dating has been confined largely to New South Wales and Queensland. Most
of the analyses have been done on plutons in the New England Orogen, but results
have also been obtained for adjacent areas, such as northeast Queensland and
volcanogenic rocks in the Sydney - Bowen Basin. In Western Australia, mafic intrusives
and some possible volcanic rocks intersected in offshore wells in the Canning and
Carnarvon basins have been dated (e.g. Reeckmann & Mebberson, 1984). In addition,
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