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Altered rhyolite lava on the beach front. Diamond Head and eroded cleft in background
Example of eroded columnar jointing at Diamond Head with honeycomb weathering in foreground
Roch arch: possibly the result of a collapsed sea cave
South of the rock arch this photo shows the two distinct lava flows, the uppermost lighter coloured one being strongly acid leached and weathered

Diamond Head - Crowdy Bay National Park

Latitude -31.717554, Longitude ,152.798291

Located in the Mid North Coast Region of NSW, nearest large town Laurieton

Source:Bob and Nancy Brownwww.brovey.yolasite.com

Link to Detailed Map

Bob and Nancy Brown (www.brovey.yolasite.com) have written an excellent article outlining a geological tour of this region and we have selected a few details here to describe the area. If you're going to Diamond Head, we suggest you download the whole tour from the above website.

Diamond Head, located in Crowdy Bay National Park, is one of the most colourful and beautiful areas on NSW's coast and is well worth a visit. The headland gained its name from the quartz rich rocks, plentiful in the area, which contain an abundance of small, perfectly formed, clear quartz crystals whose appearance resembles diamonds.

Geology

The uniqueness of the rugged Diamond Head headland is the result of a series of lava flows across the area in the Late Triassic (about 200 million years ago). The lavas were altered by fluids which modified the original minerals, and added quartz, pyrite and a little gold to the rocks. The alteration process formed areas of relatively hard, quartz-rich rock which armoured the headland against erosion. Following eruption and alteration of the lavas, magma continued to move upward through the rocks, forming small intrusions and numerous dykes. The combination of lavas, abundant small intrusions and extensive alteration is indicative that this area was on the very edge of a significant volcanic vent.

Approaching the area via the beach at the northern end of Diamond Head one can observe the yellow-to-white altered rhyolite lava on the beach front. Just south of this formation is a cleft in the headland: this has possibly formed from the erosion of a dyke as no trace of the pre-existing softer rock type is evident. There are a number of interesting phenomena to observe here: flow banding in the lava, columnar jointing and honeycomb weathering.

Getting There

Diamond Head is located in Crowdy Bay National Park on the Mid North Coast between Taree and Port Macquarie. The headland is accessible via either South Moorland or Laurieton. There are National Parks and Wildlife Service camping areas at Diamond Head and in other parts of the national park. For information re: camping fees and conditions see.

www.environment.nsw.gov.au/NationalParks


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