About 750 million years ago, a large sheet of granite formed many kilometres below the earth's surface, as molten material cooled. After about another 500 million years, this part of Australia collided with India to form part of the southern super continent, Gondwana.
Extreme pressures and temperatures deep within the Earth's crust affected the granite, turning it into the metamorphic or "changed" rock with different characteristics from granite.
This new rock was gneiss, which had a banding structure, which facilitated large parallel cracks forming as the rock cooled and later, as the continents drifted apart, the bands and cracks widened due to the stress applied.
As time went on, limestone was deposited on top of the gneiss forming many of the cliffs along the coast. It was deposited as wind blown sand dunes over the last 2 million years.
Where the limestone has eroded exposing the gneiss, and the cracks in it, water was able to penetrate the cracks leading to erosion of the soft material in the fissures, and a significant widening of the cracks. As 
they widened, the action of the water increased until the canals and channels we see today were gradually formed.
To qualify to log a find on this earthcache please send the answers to the following questions to me.
1. Based on the way these channels and the large canal were formed, do you think the rate of widening is accelerating as the gaps get wider? Please explain your reasoning?
2. Did you observe any unexpected surges or large waves washing through which surprised you with their violent action, based on the existing weather conditions.
3. Please attach a photo to your Found Log, of some aspect of the formation here (you can be creative), with you or a personal item if you prefer, included in the photo.
4. Please your answers to earthcaches@jamieson.id.au for a faster response. You can of course send via my profile but I may not see it as quickly as it will get mixed in with my watch list email.
Note: It's quite okay to log an earthcache find immediately, so that your order of finds is preserved, but I must receive your answers with a week to ten days, or your log may be deleted.