Saturday 6th October 2007

Geology and Formation. Guide: Heather Ducat

The weather was a little overcast which was a good thing following the downpour the previous afternoon.

Total of eleven people left the Briars, the site of the campout, to head towards Gunnamatta Beach to look at Cape Schanck from the distance and in profile. Heather explained how the Mornington Peninsula was formed and how it is known as a horst formation that was uplifted between two active faults. Spectacular 80 metre high cliffs display successive lava flows on the upthrow of the fault. The formations are dated from 40-50 million years old, and are capped by younger dune calcarenite which forms the Nepean Peninsula.

The weather continued to fine up as the group arrived at the Cape Schanck carpark, where everyone geared up with back packs and binoculars for the walk to Bushrangers Bay. On the walk there was plenty of bird watching and views and discussions from lookouts that gave further insight to the formation of the peninsula. The walk descended down tracks and timber steps with a crossing of Burrabong Creek and sightings of several Wallabies.

At the bottom of the walk at Bushrangers Bay the group continued along the beach for a short distance to look at the mouth of Burrabong Creek which in the past had been sealed and created freshwater limestone deposits that could be seen in the cliff faces.The group returned up the steps and tracks which got the cardiovascular system pumping.
A short walk around the carpark to several other lookouts gave a different perspective of the creation of the Cape Schanck land formation.

A short drive to the Fingal (Pines) picnic ground for a bit of lunch in the shade of an old pine tree plantation. A short walk around the Fingal circuit to several lookouts that showed exposed lava flows and distorted basalt columns with additional views of the Nepean Peninsula. and the Selwyn Fault.

The excursion revealed 28 bird species with a treat of a Bassian Thrush, several wallabies, some Pink Finger Orchids and several patches of Bird Orchids.

Contributed by Graeme Rigg (Facilitator)