12
1 General Review of Permian Sediments in Western Australia
of the times. Some acritarchs in the present study appear in great numbers in samples
otherwise poor in pollen and spores. The spores/pollen in these samples are poorly
preserved. Furthermore, these samples were vitrinite-dominated coals poor in exinite
macerals, indicating high water table, ideal conditions for wood preservation and the
thrive of algae. The few corroded saccate pollen grains found in these samples have
come from non-aquatic plants growing on higher ground.
Interestingly, acritarchs are found in fresh water bodies unlike hystrichospheres
and later in the dinoflagellates which were dwellers of a marine environment. Li et al.
(2004) discussed the different habitats of the two groups. The marine Upper Permian
of SE China was dominated by hystrichospheres (Li et al. 2004).
Remains of the alga Botryococcus were abundant in only a few samples noted for
the absence of acritarchs and abundance of pollen.
Botryococcus is regarded as a fresh water colonial alga. Cookson (1953) mentions
that Botryococcus usually inhabits fresh water lakes and ponds. However, she also
recorded its occurrence in the brackish water lagoons of the Coorong, along the coast
of South Australia. I examined coorongite, a rubbery deposit made almost solely of
the alga Botryococcus deposited in the Coorong lagoon (Glikson 1983; 1984). My
study mentions the resistance of Botryococcus to degradation and its subsequent
excellent preservation in sediments such as the Permian torbanites from the Sydney
and Carnarvon Basins. It is noteworthy that Botryococcus produces hydrocarbons
that are toxic to other algae and plankton, which may explain the absence of acritarchs
in Botryococcus-rich samples.
1.5.4 Saccate Pollen Grains
In the case of saccate pollen grains a vast number of supra-generic groups exist,
many of no practical use. Potonie (1955) divided the saccate forms into three groups,
namely:
1. POLYSACCITES: Cookson (1953)
2. MONOSACCITES: Chitaley (1951)
3. DISACCITES: Cookson (1953)
1.6 Monosaccate Forms
Leschik (1955) further sub-divided the monosaccate forms into two series based on
the presence or absence of a proximal tetrad mark. Leschik’s series are as follows:
1. TRILETESACCITES
2. ALETESACCITES
1 General Review of Permian Sediments in Western Australia
of the times. Some acritarchs in the present study appear in great numbers in samples
otherwise poor in pollen and spores. The spores/pollen in these samples are poorly
preserved. Furthermore, these samples were vitrinite-dominated coals poor in exinite
macerals, indicating high water table, ideal conditions for wood preservation and the
thrive of algae. The few corroded saccate pollen grains found in these samples have
come from non-aquatic plants growing on higher ground.
Interestingly, acritarchs are found in fresh water bodies unlike hystrichospheres
and later in the dinoflagellates which were dwellers of a marine environment. Li et al.
(2004) discussed the different habitats of the two groups. The marine Upper Permian
of SE China was dominated by hystrichospheres (Li et al. 2004).
Remains of the alga Botryococcus were abundant in only a few samples noted for
the absence of acritarchs and abundance of pollen.
Botryococcus is regarded as a fresh water colonial alga. Cookson (1953) mentions
that Botryococcus usually inhabits fresh water lakes and ponds. However, she also
recorded its occurrence in the brackish water lagoons of the Coorong, along the coast
of South Australia. I examined coorongite, a rubbery deposit made almost solely of
the alga Botryococcus deposited in the Coorong lagoon (Glikson 1983; 1984). My
study mentions the resistance of Botryococcus to degradation and its subsequent
excellent preservation in sediments such as the Permian torbanites from the Sydney
and Carnarvon Basins. It is noteworthy that Botryococcus produces hydrocarbons
that are toxic to other algae and plankton, which may explain the absence of acritarchs
in Botryococcus-rich samples.
1.5.4 Saccate Pollen Grains
In the case of saccate pollen grains a vast number of supra-generic groups exist,
many of no practical use. Potonie (1955) divided the saccate forms into three groups,
namely:
1. POLYSACCITES: Cookson (1953)
2. MONOSACCITES: Chitaley (1951)
3. DISACCITES: Cookson (1953)
1.6 Monosaccate Forms
Leschik (1955) further sub-divided the monosaccate forms into two series based on
the presence or absence of a proximal tetrad mark. Leschik’s series are as follows:
1. TRILETESACCITES
2. ALETESACCITES