The Mittagong Formation is a sedimentary rock unit in the Sydney Basin in eastern Australia.[1]

Mittagong Formation

Stratigraphic range: Triassic
TypeGeological formation
UnderliesAshfield Shale
OverliesHawkesbury sandstone
Thicknessup to 10 metres (30 ft)
Location
LocationSydney Basin
CountryAustralia
Type section
RegionMittagong
CountryAustralia
Thickness at type section15 metres

Formation edit

Laid down in the Triassic Period, it may be seen as an interval of interbedded fine-grained sandstone and shale between the Ashfield Shale (above) and the Hawkesbury sandstone (below). The maximum thickness around Sydney may be ten metres.[2] Near Town Hall railway station, the formation is 8 metres thick. In the type area at Mittagong it is 15 metres thick.

Whereabouts edit

In northern Sydney it can be seen in several areas, such as West Pymble[3] and Mount Ku-ring-gai.[4] This rock formation is associated with the critically endangered Sydney Turpentine-Ironbark Forest.[5]

See also edit

References edit

  1. ^ "Australian Museum - The Sydney Basin".
  2. ^ "Geoscience Australia".
  3. ^ Field Geology of New South Wales, Sydney Basin page 102
  4. ^ Chris Herbert. Geology of the Sydney 1:100,000 Sheet 9130
  5. ^ "Sydney Turpentine-Ironbark Forest".