South West Solitary Island or Groper Island is an island found off the
New South Wales North coast and inside the
continental shelf
A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...
. It is located 18 km north-east of
Coffs Harbour
Coffs Harbour is a city on the Mid North Coast of New South Wales, Australia, north of Sydney, and south of Brisbane. It is one of the largest urban centres on the North Coast, with a population of 78,759 as per 2021 census. The Gumbaynggirr ...
and about 18 km south-south-east of
Woolgoolga.
The island is part of the Solitary Islands Marine Park established 2 January 1998 and managed by the NSW Maritime Parks Authority.
Rocks on South West Solitary Island consist of repeating beds of mudstone and sandstone. The sandstone is medium to coarse grained. Some beds are 5 to 10 cm thick, whereas others are up to 3 m thick. The strike of the beds is between 350° and 60° with dipping at 41° to 67°. There is an anticline with syncline on the southwest of the island. Tectonically it is part of the
Coffs Harbour Block which in turn is part of the
New England Orogen
The Hunter-Bowen Orogeny was a significant arc accretion event in the Permian and Triassic periods affecting approximately 2,500 km of the Australian continental margin.
The Hunter-Bowen Orogeny occurred in two main phases, a Permian accretio ...
.
References
Islands of New South Wales
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