Rocky Beach, Port Macquarie, Macquarie Co., New South Wales, Australia
|Latitude & Longitude (WGS84):||31° 26' 18'' South , 152° 55' 32'' East|
|Latitude & Longitude (decimal):||-31.43830,152.92544|
|Köppen climate type:||Cfa : Humid subtropical climate|
The Rocky Beach Metamorphic Melange is located at Rocky Beach, Port Macquarie on the mid north coast of New South Wales, approximately 400 km north of Sydney.
The rock group forms part of the Port Macquarie block (Och et al. 2003), located in the eastern New England Fold Belt and is notable for the presence of well-exposed high-pressure metamorphic rocks and a wide variety of igneous rocks, including pillow basalts of MORB (Mid Ocean Ridge Basalt) affinity, and minor mafic and intermediate calc- alkaline intrusions, embedded in lenses of serpentinite melange. It covers an area of just under 1 hectare.
Near the north end of Rocky Beach a 'melange-in-melange' structure preserving serpentinite masses that have invaded the Watonga Formation, which has also enveloped two bodies of chlorite- actinolite schist, surrounded by highly schistose Port Macquarie Serpentinite, contain inclusions of lawsonite eclogite, omphacitite, blueschist, and tremolite marble. Although these exotic high-pressure metamorphic rocks are known from serpentinite bodies elsewhere across eastern Australia their occurrence is unique because some of these tectonic blocks, namely eclogite, contain a mineral called lawsonite, which have only been identified in 10 localities worldwide. The Rocky Beach Metamorphic Melange type area occurs at the north end of Rocky Beach. The unit comprises blocks of multiply deformed polymetamorphosed high-pressure metamorphic rocks (Och et al. 2003) of mafic igneous parentage low-grade blocks of sedimentary and basaltic rocks derived from the Watonga Formation, and a narrow slice of antigorite serpentinite, set in a multiply deformed chlorite- actinolite schist matrix.
The location is an internationally important geoheritage site.
12 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Permian - Cambrian|
252.17 - 541 Ma
Age: Paleozoic (252.17 - 541 Ma)
Comments: igneous mafic intrusive; igneous mafic volcanic; synthesis of multiple published descriptions
Lithology: Igneous mafic intrusive; igneous mafic volcanic
Reference: Raymond, O.L., Liu, S., Gallagher, R., Zhang, W., Highet, L.M. Surface Geology of Australia 1:1 million scale dataset 2012 edition. Commonwealth of Australia (Geoscience Australia). 
272.3 - 298.9 Ma
|Paleozoic sedimentary rocks|
Age: Cisuralian (272.3 - 298.9 Ma)
Comments: New England Fold Belt
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529.