© Copyright, Moffitt 2000 Scheibner & Basden 1986 Figure 3.2 Schematic structure map of the Sydney © Copyright, Geoscience Australia 2013: www.ga.gov.au/oceans/ea_ofs_sdny_Strat.jsp Figure 3.3 Stratigraphy of the Sydney Basin. Southern Coalfield The general stratigraphy and depositional environment of the Southern Coalfield above the Shoalhaven Group comprises: Wianamatta Group—formed in a shallow marine to alluvial floodplain that is today exposed across much of the Cumberland Basin Hawkesbury Sandstone—formed in an alluvial environment, the outcrop of which dominates the sandstone formations around Sydney Narrabeen Group—formed in estuarine and alluvial environments, with lithic and quartzose sandstones, shales and mudstones Illawarra Coal Measures—formed in an alluvial and deltas, with the economic coal seams. The current economic coal resources of the Southern Coalfield are located within the upper half of the Illawarra Coal Measures. These economic resources consist of four seams, which are shown in Table 3.1. Table 3.1 Major coal seams of the Southern Coalfield. Seam Thickness (m) Mining Use Interburden thickness Typically now m, but historically Room-and-pillar Thermal and 30–500 m Bulli 2–5 and longwall coking mining Accessible resource to a depth of about 800 m Limited mining Thermal and Balgownie 1.5–2 5–30 m Bulli Seam in the past coking Room-and-pillar Thermal and 30–50 m below Bulli Wongawilli 6–18 and longwall coking Seam mining Limited mining 70–80 m below Tongarra ~3 Thermal in the past Wongawilli Seam
© Copyright, Moffitt 2000 Scheibner & Basden 1986 Figure 3.2 Schematic structure map of the Sydney © Copyright, Geoscience Australia 2013: www.ga.gov.au/oceans/ea_ofs_sdny_Strat.jsp Figure 3.3 Stratigraphy of the Sydney Basin. Southern Coalfield The general stratigraphy and depositional environment of the Southern Coalfield above the Shoalhaven Group comprises: Wianamatta Group—formed in a shallow marine to alluvial floodplain that is today exposed across much of the Cumberland Basin Hawkesbury Sandstone—formed in an alluvial environment, the outcrop of which dominates the sandstone formations around Sydney Narrabeen Group—formed in estuarine and alluvial environments, with lithic and quartzose sandstones, shales and mudstones Illawarra Coal Measures—formed in an alluvial and deltas, with the economic coal seams. The current economic coal resources of the Southern Coalfield are located within the upper half of the Illawarra Coal Measures. These economic resources consist of four seams, which are shown in Table 3.1. Table 3.1 Major coal seams of the Southern Coalfield. Seam Thickness (m) Mining Use Interburden thickness Bulli 2–5 Room-and-pillar and longwall mining Thermal and coking Typically now m, but historically 30–500 m Accessible resource to a depth of about 800 m Balgownie 1.5–2 Limited mining in the past Thermal and coking 5–30 m Bulli Seam Wongawilli 6–18 Room-and-pillar and longwall mining Thermal and coking 30–50 m below Bulli Seam Tongarra ~3 Limited mining in the past Thermal 70–80 m below Wongawilli Seam
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