This is an EarthCache and has special requirements for logging it. You cannot log a Found It without responding to the logging requirements set out below.
Only one find claim per Message. Each Geocacher claiming a find must submit an individual response. One team can not lodge a response on behalf of a group of people.
Hopefully, after visiting this site, you will have an expanded appreciation of the wonders of our natural environment, and recognise that the environment here has a rather rare geological feature.
Pegg’s Lookout is at the southern end of what is known as Toohey Forest Park: Toohey Mountain at the northern end is its highest point. The Toohey Forest area is made of tough, very old quartzite formed 380 million years ago when the coastline was far to the west and the region here was deep under ocean. Enormous forces shaped the ancient ocean floor sediments, and gave us the resulting mountains around south-east Queensland. Over the millions of years since, weathering has eroded the mountains significantly to produce the relatively flat structures we stand upon today.
At and around GZ, you can observe large pale quartz-sandstone boulders: they rest along the hill top as well.
Sandstone is a sedimentary rock formed by the cementation of grains of sand, called clasts, typiclly 0.06 to 2 mm in diameter. Often this cementing material is calcium carbonate, but also silica or iron oxides can be the cement.
The mineral, quartz, is a mineral that is highly resistant to weathering, both chemical and physical. For the chemically minded, it is composed of silicon and oxygen atoms in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar.
Quartz makes up 95% of the grains in the sandstone rocks here. This is somewhat rare: normally quartz makes up to 50% of the grains in sandstone. So they are not common in the geologic record because the required conditions are difficult to achieve. You might like so search Google for more information about quartz-sandstone.
The boulders here appear well-rounded and weathered, effects likely due to their long exposure to the elements.
From measurements at the site (See HERE) an average clast (grain) size of 2mm was identified although some larger, rounded, pebbly clasts (average- 5mm) could be observed throughout.
These large quartz-sandstone boulders date to the Triassic-Jurassic eras (somewhere around 231 million years ago). They are relatively younger than the rock you could see over at the old quarry (used in the construction of the South-East Freeway during the 1970s) behind the Salisbury Hotel, which were formed some 380 million years ago.
Find GZ for this earth cache. It is on the track – don’t wander off into the bush. As you walk up the stairs from the disignated Parking Area towards Pegg’s lookout, you will see a rather large boulder in front of you – distinguished by a cave. This is your target for observation and exploration.
- Give a rough estimation of its size (height, width and length).
- Touch the surface of the rock and describe what you feel (texture).
- Compare the colour of the rock on the outside, to the colours of the rock on the inside roof of the “cave”.
- What is significant about the rocks you see around GZ? (See description above.)
- Take of photo of yourself OR your GPS to show a view of GZ. Include it in your message, but please do not post it in your log, it might give too much away.
When you have your response to the above questions, please, if possible, MESSAGE us, using the link at the top of the page underneath the name of the Cache. We prefer the MESSAGE method, as apparently, we don't respond to emails very well, but messages we do. We will contact you by MESSAGE once your MESSAGE has been received. But you can log your find in the meantime, and just say that you have MESSAGED your answers to the COs.
Happy Earthcaching!