Phillip Island Excursion Site1: The Nobbies

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Aerial view of The Nobbies
Aerial view of The Nobbies

The Nobbies, a popular tourist spot, is the most south-westerly point of Phillip Island and is named after the large rock knobs sticking out of the water. Especially prominent is Seal Rocks where an Australian Fur Seal colony lives. There is a tourist centre with a café, shop, display, and toilet facilities. Boardwalks make for easy access.

The Nobbies, Phillip Island
The Nobbies, Phillip Island
The Nobbies are part of the Older Volcanics and you can see in each of the lava flows a prominent, clay-rich, chemically altered profile which consists of massive red to white layers beneath the base of the black basalt of the overlying flow. Individual lava flows here are probably no more than 1–2 metres thick.

Notice the prominent shore platform on the peninsula between The Nobbies and Phillip Island and around the peninsula to the east and to the north. The platform is also composed of black basalt and you can see places where the waves have eroded out the softer weathered basalt leaving overhangs and tunnels. This sort of erosion would have produced The Blowhole which is visible a little way around to the east of the point.

The wildlife you can observe from the boardwalk is most interesting and includes gulls, fairy penguins, shearwaters, and snakes.

Significance

These deposits illustrate the extent of the volcanic eruptions with the thickness of one lava flow indicated by the length of the columns. The holes (vesicles) in the basalt point to the release of gases during the eruptions. The clay rich ‘weathering profile’ may be another indication of concurrent sedimentation with the volcanic eruptions. The flat surfaces on the tops and bottoms of the lava flows contrast with the highly irregular surface of the ladnscape that exists now. This indicate that there was not much time between the flows, so there was not much erosion of the surfaces.

Guide available as a booklet
This entry is taken from the geological excursion guide for Phillip Island. The complete guide is available as a booklet on creation.com Aussie store.