102
3 The Microfloral Assemblages—Their Environmental and Climatic …
Cristatisporites, and the pteridosperm Marsupipollenites, and a few disaccate pollen
producing plants. The first appearance of Striatiti representing the Glossopteris
flora appeared at the end of the Sakmarian. The spores which represent ferns and
Marsupipollenites, a Pteridosperm, both groups form understory plants in the Cordaitalean swamp forest, with the odd Equisetum-like plant represented by the spores
of Cycadopites cymbatus.
Other pollen types occurring in small numbers are as mentioned: occasional disaccate striatiti; the disaccate form Illinites and trilete spores such as Apiculatisporites
levis, Retusotriletes diversiformis and the zonate spore Cristatisporites. Assemblage
No. 1 corresponds To Balme’s (1964) Nuskoisporites assemblage and Evan’s (1967)
Stage I. The same pollen/spore assemblage was recorded from the Nangetty Formation in Perth Basin, which was dated as Sakmarian (Playford 1959). On the basis of
correlation between the samples dominated by the Parasaccites assemblage and the
Nangetty formation, Sakmarian age is assigned to Unit I in Collie–Muja Basin.
Helby (1967) in discussing the Permo-Carboniferous boundary in Australia brings
in the microfloral factor, namely the introduction of the ‘Potoniesporites’ microflora
following the decline of the ‘Lycopsid’ microflora, “an event which appears to be
intimately associated with the widespread development of ‘glacigene’ sediments…”
Helby regarded the Potoniesporites microflora as the top of the Carboniferous, “the
closest, available approximation to, and most convenient location for the top of the
Carboniferous system in Australia”. Potoniesporites represented a certain vegetation
which gave way to the Parasaccites-dominated plant community, which marks the
Lower Permian. Parasaccites’ a monosaccate distinctive pollen is typical of the
Cordaitales dominating the Sakmarian tillites (‘glacegene sediments’).
Cordaitales plant remains are known from coal deposits in the Carboniferous and
Permian of Western Europe, North America, North China and Russia. Fossil evidence
indicates that these plants attained over 30 m in height (Cridland 1964) had slender,
well-developed branches with spirally arranged, leathery leaves of parallel venation.
Leaves attained a length of 1 m. Cridland (1964) reconstructed Codaitalean plants
from fossil remains (Fig. 3.1).
In summary, the Sakmarian floral community can be seen as dominated by the
cordaitales tall trees with the understory of Pteridosperms and ferns. Their abundance
and preservation enable their identification and the reconstruction of the post-glacial
plant scene.
In bore B, Collie Basin (Fig. 3.3)
In bore D, Collie Basin (Fig. 3.2)
In Sue-1 Bore, South Perth Basin (Fig. 3.4)
Chart of individual pollen species in Collie bore B (Appendix A.1 and A.2)
While Parasaccites gondwanensis is a dominant form in the tillite sediments,
Microbaculispora tentula becomes more abundant at the top of the tillites and the
overlying sandstone. P. gondwanensis, on the other hand, decreases in quantity
towards the top of the tillites and the overlying sandstones, where it drops to about
10% of the total microfloral assemblage from 80% in the tillites. There is a link
between Parasaccites and cold climate.
3 The Microfloral Assemblages—Their Environmental and Climatic …
Cristatisporites, and the pteridosperm Marsupipollenites, and a few disaccate pollen
producing plants. The first appearance of Striatiti representing the Glossopteris
flora appeared at the end of the Sakmarian. The spores which represent ferns and
Marsupipollenites, a Pteridosperm, both groups form understory plants in the Cordaitalean swamp forest, with the odd Equisetum-like plant represented by the spores
of Cycadopites cymbatus.
Other pollen types occurring in small numbers are as mentioned: occasional disaccate striatiti; the disaccate form Illinites and trilete spores such as Apiculatisporites
levis, Retusotriletes diversiformis and the zonate spore Cristatisporites. Assemblage
No. 1 corresponds To Balme’s (1964) Nuskoisporites assemblage and Evan’s (1967)
Stage I. The same pollen/spore assemblage was recorded from the Nangetty Formation in Perth Basin, which was dated as Sakmarian (Playford 1959). On the basis of
correlation between the samples dominated by the Parasaccites assemblage and the
Nangetty formation, Sakmarian age is assigned to Unit I in Collie–Muja Basin.
Helby (1967) in discussing the Permo-Carboniferous boundary in Australia brings
in the microfloral factor, namely the introduction of the ‘Potoniesporites’ microflora
following the decline of the ‘Lycopsid’ microflora, “an event which appears to be
intimately associated with the widespread development of ‘glacigene’ sediments…”
Helby regarded the Potoniesporites microflora as the top of the Carboniferous, “the
closest, available approximation to, and most convenient location for the top of the
Carboniferous system in Australia”. Potoniesporites represented a certain vegetation
which gave way to the Parasaccites-dominated plant community, which marks the
Lower Permian. Parasaccites’ a monosaccate distinctive pollen is typical of the
Cordaitales dominating the Sakmarian tillites (‘glacegene sediments’).
Cordaitales plant remains are known from coal deposits in the Carboniferous and
Permian of Western Europe, North America, North China and Russia. Fossil evidence
indicates that these plants attained over 30 m in height (Cridland 1964) had slender,
well-developed branches with spirally arranged, leathery leaves of parallel venation.
Leaves attained a length of 1 m. Cridland (1964) reconstructed Codaitalean plants
from fossil remains (Fig. 3.1).
In summary, the Sakmarian floral community can be seen as dominated by the
cordaitales tall trees with the understory of Pteridosperms and ferns. Their abundance
and preservation enable their identification and the reconstruction of the post-glacial
plant scene.
In bore B, Collie Basin (Fig. 3.3)
In bore D, Collie Basin (Fig. 3.2)
In Sue-1 Bore, South Perth Basin (Fig. 3.4)
Chart of individual pollen species in Collie bore B (Appendix A.1 and A.2)
While Parasaccites gondwanensis is a dominant form in the tillite sediments,
Microbaculispora tentula becomes more abundant at the top of the tillites and the
overlying sandstone. P. gondwanensis, on the other hand, decreases in quantity
towards the top of the tillites and the overlying sandstones, where it drops to about
10% of the total microfloral assemblage from 80% in the tillites. There is a link
between Parasaccites and cold climate.