This EarthCache is based around the formation of cliffs through lithification and the weathering since the formation.
There is no need to climb any cliff face while attempting this cache. Please be wary.
The steps down are steep in some places which is reflected in the terrain rating. Observe all signs on the way down.
The cliffs of Innes National Park and surrounding areas were formed from large underwater sand dune systems that once lined the length of the coast. The now lithified sand dunes are what make up these cliffs. Evidence of the previous, larger beach layout can still be seen at the bases of the cliffs.
These cliffs are made up of calcarenite, a type of limestone. Calcarenite is predominantly made up of detrital sand, consisting of corals and shells, as well as other types of grains.
Lithification is a natural process that occurs underwater when sediments such as clay and sand are slowly compacted into solid rock from the weight of overlying sediments.
For a rock to be fully lithified it must go through two stages:
- The aforementioned weight of overlying sediments compressing those beneath it and pushing out the water between the spaces of the sediments.
- Fluids carrying cementing compounds flowing between the loose particles, binding them and cementing it in place.
(https://www.researchgate.net/figure/Lithification-process-of-rock-in-nature_fig1_338061167)
The coastal orientation in the region was a massive factor in setting lithification in motion. The coastal orientation faces towards the South-West, exposing the area to large swells and strong winds.
Since the sea levels dropped and exposed the rock, the cliffs have been subject to erosion and weathering, with wave cut platforms dominating the coastline.
Wave cut platforms occur in cliffs when hit with powerful waves. A wave cut cliff is typically a steep rock face. After continuous hits by the waves a notch gets carved into the cliff and can become a line of weakness.
Observe all given information and see the questions below to complete this EarthCache.
Logging Requirements:
Look at the cliff face and answer the following questions:
- Describe the notch, what is the depth and height?
- Is there more than one notch? What do you think this means?
- Can you see collapse associated with the notch?
- Observe the calcarenite and describe the size of the grain structure.
- Handle sand from the beach and compare grain structure with the limestone. Do you see any similarities?
- Post a picture of yourself, your stamp or personal item with the cliffs visible in the background. (Mandatory to prevent armchair solvers)
Please send messages via Geocaching message centre or to my email, answers posted in the logs will be deleted.
You can log the find immediately, if answers are supplied to CO within 14 days.
Stay safe and vigilant and happy hunting!
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