RANDALLS BAY POINT

Randalls Bay Point offers amazing views of the Huon Estuary, Randals Bay and Garden Island. 

This headland is made of of two predominant groups of rock. 

Quantanery Gravel Deposits

The surface layers are mostly made up of quantanery gravel deposits. At randalls bay these deposits vary between 2 to 6 meters deep. The gravel contains pebbles of quartz (chalcedony, agate) chert, quartzite, dolerite and mudstone in a sandy clay matrix and these range from sand grade to boulders 5 feet across. Quartz pebbles are most plentiful (83%) (including agate 8%), with smaller amounts of quartzite (10%), mudstone (2%) and dolerite (5%). 

Quartz and Feldspatic Sandstone

Quartz and Feldspatic Standstones form the bulk structure of this headland. Its thickness ranges from 20 to 27 meters in the Randalls Bay area. The rock is a medium grained, well sorted, massively cross bedded quartz sandstone with some limonite concretions and occasional green and brown clay pellets. 

Rock Erosion

Randalls bay point offers some good examples of different types of erosion. Erosion of rock can be broadly broken down into the following categories:

• Hydraulic Action - Where the force of water wears away the rock from underneath causing the rock to collapse
• Abrasion - Where rocks smash into one another causing the rock to break down into smaller and smaller parts. This can also be caused by high winds moving smaller particles such as sand causing an effect like sandblasting. 
• Solution - Where by acids in water causes the rock to break down chemcially over time
• Corasion - Where wave action beating upon coastal rocks causes small pieces to break off
• Corosion - Where solution or chemcial differences between the pH of the water and the consituent rock causes a reaction. 

Accessing the GZ

Accessing the GZ is via a walking path from Randalls Bay Picnic area. There is plenty of room to pull into. There is even some BBQ's and a Toilet if needed. 

Park at S43 14.720  E147 07.119

There is a rock staircase to the right of the blue sign that leads to the top of the point. From there follow the formed path to the GZ. The staircase is narrow in sections and its advisable to take your time and wear appropriate footwear.  

Logging this Earthcache

To gain permission to log this Earthcache you must answer a few questions to demonstrate your understanding of what rock makes up this area as well as the physical effects the local environment is having on the geology here. You will need to read the above information as well as visit the location to obtain your answers. 

Please do not post the answers to the following questions in your log. Please send them direct to me via the message centre or via email. 

At the GZ you will find yourself standing upon an unusually shaped piece of rock. Please answer the following questions about this rock. 

Q1) Describe the features of the rock you are standing on and why do you think this type of rock is here?

Q2) Describe the shape of the surface erosion and explain which type(s) of erosion that may have caused this? 

Q3) OPTIONAL: For a bit of fun the eroded surface rock can look a bit like an organ contained within the human body. Which organ you you think this rock looks like?

Q4) OPTIONAL: Please share a photo of your GPSr and/or yourself at the point, but please do not show the rock formation. 

Feel free to log your find as soon as you submit your answers. I will respond via message centre or email as soon as I can giving permission or asking for any follow up information as needed.