This Earth Cache is designed to bring you to a great place on the Western Australian Southern Coast and hopefully make a simple to understand a small bit of our past and the land that we live on, especially around our rugged coast line. This can be a very dangerous coast so all precautions must be taken for your own safety, remember KING WAVES can kill! You will also need to have a high clearance four wheel drive vehicle to get close to GZ, once at the end of the road/track you can take a short walk to GZ if the weather is suitable and make your finding and observations here, take some time out and have a good look around or maybe even throw a line in for a fish!
Fanny Cove is situated on the eastern side of Stokes Inlet, just a few kilometres from the estuary opening but on the coast facing almost due south, however nicely protected by the headland where the earth cache can be found.
At GZ you will find some interesting colours and layout of rocks, I believe the black Basalt or Dolerite you see was caused by volcanic activity and the quartz running off at nearly 90 degrees has some orange coloration. The major rocks in this section of Stokes National Park are migmatites typiucal of those that have suffered intense wrenching and metamorphism. Migmatite is a rock formed when a metamorphic rock is partially melted. This creates a mixture of unmelted metamorphic rock and melted and recrystallised igneous rock. (Ref: Geology of Westerrn Australia's National Parks 4th Edition, Peter Lane,)
Geology:-
The estuaries in the area are of very recent origins geologically. During the last major glaciation of the Pleistocene period (the last 2 million years), and only 20,000 years ago, the sea level was more than 100 metres lower than it is now. For some kilometres beyond the present coastline there was dry land, across which the rivers flowed to the sea through river valleys, the location of which is indicated by submarine canyons along the edge of the continental shelf. With the melting ice caps the sea rose to its present level about 6,000 years ago flooding the estuaries, and for some time after sea levels may have been about 2 metres higher than it is now.
The greater part of this area lies within the Albany-Fraser geological Province, off the south eastern edge of the ancient Yilgarn Block. The basement rocks are Proterozoic granite rocks (Migmatites, more than 1200 million years old), but near the coast these are covered by the Eocene Pallinup Siltstone (40 million years olds).
The Inlet is in a deep valley between the high Pleistocene limestone dunes, through which the rivers maintained a channel. It is located along a probable fault structure, which may explain the deep incision of the river valley and the sighting of some Basalt seams running through the granite at GZ.
To log this Earth Cache you will need to answer the questions below.
1. What can you say about the black rock you see at GZ?
2. What other rock features can you observe at and around GZ?
3. Include a photo of you and or your team or a significant item, such as your GPS shown with significant part of the sight in view.
You may log this cache after your visit however you should send the answers and the photo to me within say 10 days of logging the cache, via my profile, failure to do so may result in me deleting your log. Enjoy your visit to Fanny Cove and happy fishing, swimming or camping and caching.