Our aim with this particular Earth Cache is to take you to an interesting location and teach you some basics, we have presented this earth science lesson on a basic level to accommodate those who avoid EC’s ‘cos they are too hard’ and also to accommodate those travelling with Children (TAWKers) who incorporate Earth caches into their curriculum.
Our Geo children think that a fancy French word to describe a landform in Lang Lang is a little bit funny! (Lang Lang isn’t fancy)
The origin of the name Lang Lang is debated. In the Australian Aboriginal Woiwurrung language, the name Lang Lang, also spelled Laang Laang, meant "stones" or "stony". An alternate explanation is that the town is named in honour of an early settler in the region, called Lang.
Lang Lang is known for its vast sand deposits and extremely fertile Peaty soils to its North.
Today’s Earth Science lesson takes you to an out of the way beach with some small Cliffs. Please park at the designated parking space and walk along the beach rather than through the caravan park.
Please note, these cliffs are unstable, please take note of the warning signs, observe from a distance and stay out of harms way.
Please also note, although not essential low tide (or near) will make the walk to GZ easier.
So what does this fancy French word mean?
A chenier or chénier is a sandy or shelly beach ridge that is part of a strand plain, called a “chenier plain,” consisting of cheniers separated by intervening mud-flat deposits with marsh and swamp vegetation. Cheniers are typically 1 to 6 m high, tens of km long, hundreds of metres wide, and often wooded. Chenier plains can be tens of km wide. Cheniers and associated chenier plains are associated with shorelines characterized by generally low wave energy, low gradient, muddy shorelines, and abundant sediment supply. The name is derived from the French word for wood, “chêne,” meaning oak, which grows on chenier ridges within southwest Louisiana.
The eroding cliffs consist of Upper Tertiary ferruginous sandstones with mottled clay and a soil horizon above. Sand from the cliffs has covered the mudflats, which supported mangroves at the time of Smythe's survey of the coast in 1842. The chopping and burning of mangroves for ash ("barilla"), which was shipped to England for use in soap manufacture, was extensive in the 1840's and 1850's from this easily accessible area and probably accounts for the disappearance of mangroves.
Active shoreline recession is an ongoing source of hazard along this area’s shoreline. Recession of this coastline more than likely pre-dates European occupation of Western Port. Prior to draining and clearing The Great Swamp, scrub existed along the shoreline and coastal margin and would have provided some stability and resistance to the exposed earth materials making up the low cliff morphology. This would probably have resulted in lower rates of overall shoreline recession than experienced at present.. The erosion of the low earth cliffed shorelines is a result of direct wave action and processes involving wetting and drying of the cliff material as a result of tidal submergence/emergence, wave splash, runoff and groundwater outflows. These processes result in desiccation of the clay and organic materials which make up the low earth cliffs. Shrinkage and stress release fractures in the exposed material are susceptible to detachment by wave pressure during surges.
These particular cliffs show good soil profile so we will take the opportunity to leave a visual explanation of the layers you can see.
To log this Earthcache we require you to read the cache notes provided and to stay safe while visually exploring GZ, then, to the best of your ability message us with the following answers;
1. Is a Chénier an accurate name for the land form around GZ, explain why or why not?
2. What examples of Active shoreline recession can you see?
3. Do you believe Active shoreline recession in this area is fast or slow, explain why or why not?
4. Name one of the soil layers you can see in the profile of the cliff, explain how you know it is this particular layer?
5. A photo of your Team, GPS near GZ with your log and answers. (optional)
You are welcome to log your answers straight away to keep your TB's and Stats in order but please message us with your answers within a couple of days. Cachers who do not fulfil the Earth Cache requirement will have their logs deleted.
Acknowledgments:, Wikipedia, http://www.seccca.org.au, Heritage council of Victoria.
