Munmorah Conglomerate is a
geologic formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...
in the
Sydney Basin
The Sydney Basin is an interim Australian bioregion and is both a structural entity and a depositional area, now preserved on the east coast of New South Wales, Australia and with some of its eastern side now subsided beneath the Tasman Sea. ...
in eastern
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
. This stratum is up to 140 metres thick. Formed in the early-
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...
, it is part of the
Narrabeen Group
The Narrabeen group of sedimentary rocks occurs in the Sydney Basin in eastern Australia. This series of rocks was formed in the Triassic Period.
Geology
It includes various rock types including lithic sandstone, quartz sandstone, siltstones, ...
of sedimentary rocks. This formation includes medium to coarse-grained
sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicates) ...
and
conglomerate. With minor amounts of
siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...
and
claystone
Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone, slate, and shale. Most of the particles of which the stone is composed are less than and are too sm ...
. Below the Munmorah Conglomerates are
Newcastle Coal Measures, originating from the
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...
.
See also
*
Sydney Basin
The Sydney Basin is an interim Australian bioregion and is both a structural entity and a depositional area, now preserved on the east coast of New South Wales, Australia and with some of its eastern side now subsided beneath the Tasman Sea. ...
*
Terrigal Formation
The Terrigal Formation is a geologic formation in the Sydney Basin in eastern Australia. Commonly seen in the Central Coast region, this stratum is up to 330 metres thick. Formed in the early to mid Triassic, it is part of the Narrabeen Group of ...
*
Newport Formation
The Newport Formation is a geologic formation outcropping in the Sydney Basin in eastern Australia. This stratum is up to 49 metres thick. Formed in the mid-Triassic, it is part of the Narrabeen Group of sedimentary rocks.
See also
* Sydn ...
*
Narrabeen group
The Narrabeen group of sedimentary rocks occurs in the Sydney Basin in eastern Australia. This series of rocks was formed in the Triassic Period.
Geology
It includes various rock types including lithic sandstone, quartz sandstone, siltstones, ...
References
Geologic formations of Australia
Triassic Australia
Sandstone formations
Geology of New South Wales
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