Buckley Formation

The Buckley Formation contains coal beds and was therefore referred to by Grindley (1963) as the Buckley Coal Measures (Young and Rybum 1968). The name was taken from Buckley Island near the head of the Beardmore Glacier where Frank Wild discovered coal seams during Shackleton s trek to the South Pole (1907-1909) (Section 1.4.2). The lower part of the Buckley Formation consists of sandstone which Barrett (1969) redefined as the Fairchild Formation described above. The Buckley Formation is overlain disconform-ably by the sandstones and noncarbonaceous mudstones of the Fremouw Formation of Triassic age (Table 10.7). 

The sandstones of the lower part of the Buckley Formation are mainly arkosic and grade up-section... 

Table 10.9 Averagechemical composition to fourvolcaniclastic sandstones from the upper Buckley Formation (Permian) in the central Transantarctic Mountains (Barrett et al. 1986 Table 11)...

The sandstones of the Buckley Formation were deposited on a slowly aggrading alluvial plain, whereas the shales and mudstones accumulated in lakes and ponds (Barrett 1969 Barrett et al. 1986). The volcaniclastic component of the sandstones was probably... 

The Fremouw Formation in Table 10.7 is the oldest unit of Triassic age in the Beardmore area of the central Transantarctic Mountains. It was named by Barrett (1969) for Fremouw Peak which is located south of the Prebble Glacier in the Queen Alexandra Range in Fig. 10.14. The Fremouw Formation is composed of sandstones and mudstones that rest disconformably on the Buckley Formation (Barrett et al. 1986). The basal beds of the Fremouw Formation are composed of quartz sandstone and greenish-gray mudstone. This part of the formation contains vertebrate fossils that were discovered and described by Barrett et al. (1968b), Elliot et al. (1970), Kitching et al. (1972), and Hammer et al. (1986). The vertebrate fossils include bones of both reptiles and amphibians that occur as channel lag deposits in the basal Fremouw at Coalsack Bluff identified in Fig. 10.13. 

The chemical composition of the tuff in the FaUa Formation in Table 10.10 resembles the composition of volcaniclastic sandstone of the Buckley Formation (Table 10.9). Both rock types are silica- and aluntina-rich with low concentrations of FeO, MgO, and CaO and comparatively high concentrations of alkali oxides. Barrett et al. (1986) concluded that the tuff of the Falla Formation has a rhyolitic composition. Table 10.10 also contains the chemical analysis of a trachyte pebble from the Falla Formation on Mt. Falla. 

The average values on the PDB scale of calcite in samples of carbonate rocks from the Beacon Supergroup in the central Transantarctic Mountains in Table 11.2 range from -24.5 %o (Alexandra Formation) to -28.4%o (Buckley Formation). The evident depletion in relative to oxygen in marine calcite is strong evidence that these calcites were not precipitated from seawater. This conclusion applies even to the calcite in the Alexandra Formation which contains trace fossils that indicate that the rocks of this formation were deposited... 

The 5 values of calcite in the Fairchild and Buckley formations in Table 11.3 are negative although only three samples from these formations were analyzed. Nevertheless, this evidence indicates that plant debris was buried with the sediment and was partly converted into carbon dioxide that dissolved in the pore water. 

The geology of Coalsack Bluff was described by Collinson and Elliot (1984) who also published a large-scale map of the nunatak which is only 5 km long and 2 km wide. The rocks exposed at Coalsack Bluff include the upper part of the Buckley Formation and the lower part of the overlying Fremouw Formation for a total thickness of approximately 500 m. The sedimentary rocks of Coalsack Bluff were intruded by three sills of Ferrar Dolerite. Four whole-rock K-Ar dates, cited by Collinson and Elliot (1984), range from 170.1 2.0 to 182.3 3.2 Ma and conhrm a Middle Jurassic age for these rocks (lUGS 2002). 

Fig. 11.19 An unusually thick deposit of bituminous coal of Permian age in the Beardmore Glacier area of the Transantarctic Mountains. The coal at this location is 2.7 m thick and is over-lain by light-colored sandstone of the Buckley Formation. The chemical composition of coal from several sites in the...

The MacAlpine Hills in Fig. 13.21 are located along the south side of the upper Law Glacier which flows into the Bowden Neve between the Queen Elizabeth and Queen Alexandra ranges. Mt. Achernar is located at the junction of the MacAlpine Hills and the Lewis Cliff in Fig. 13.22. It consists of flat-lying sandstones and coal seams of the Permian Buckley Formation which was intruded by three sills of the Ferrar Dolerite. The elevation of the summit plateau of Mt. Achernar is 2,691 m a.s.l. while its base is at 2,000 m. The sills are exposed on the steep slopes of two large cirques that face the Law Glacier in Fig. 13.23. 

Fig. 13.22 Mount Achernar at 84°12 S and 160°56 E contains three sills of Ferrar Dolerite which intruded srmdstones of the Permian Buckley Formation. The underlying basement rocks ace not exposed in this area. Mount Achernar is located a short distance west of Coalsack Bluff (Section 11.2.2 Fig. 11.9B) and of Mt. Sirius which contains a deposit of Neogene till on its summit Excerpt of the topographic map Buckley Island, Antarctica SV 51-60/3 published in 1967 by the US Geological Survey...

Fig. 13.23 Mount Achernar in the Queen Alexandra Range contains three sills of the Ferrar Dolerite which intruded the Buckley Formation of the Beacon Supergroup. The base of the...

The base of the lowest sill ( 1) is not exposed and the upper contact of this sill is covered by scree. At 59 m above the base of siU 1 the sediment of the Buckley Formation is baked. ... 

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