Welcome to Westridge Outlook, home of a large rock outcrop and a boardwalk.
There are information signs around the boardwalk which will help with the cache.
This is an Earthcache without a physical container but the questions must be answered and sent to the CO before logging.
Once upon a time 300 million years ago this rock starred in its first scene.
An underwater beginning...….
Surprisingly, this hard rocky outcrop started life as a soft ooze on the deep ocean floor, east of the ancient Australian continent. Nearby, layers of mud from the continent were also being deposited.
The Earth is made up of roughly a dozen major plates and several minor plates. The Earth is in a constant state of change. Earth's crust, called the lithosphere, consists of 15 to 20 moving tectonic plates. This movement is called plate motion, or tectonic shift.
Mountains result from the application of tectonic forces to rocks, usually sedimentary or volcanic rocks. (These may be changed to metamorphic rocks as mountain‐building progresses, and at times metamorphic rocks can be pushed into mountains). Mountain‐building on continents is associated with intense deformation, folding, and faulting, usually along convergent plate boundaries. All around you can see various mountains and ranges including the D’agular Range to the North and The Great dividing range to the west, which is 3500 klm long (Wikipeadia).
The Silica rich ooze hardened to become Quartzite, Quartzite is a metamorphic rock formed when quartz-rich sandstone or chert has been exposed to high temperatures and pressures. Such conditions fuse the quartz grains together forming a dense, hard, equigranular rock (Flexible learning, Aukland). The mud was hardened into Argillite. Argillaceous rocks are basically lithified muds and oozes. They contain variable amounts of silt-sized particles. The argillites grade into shale when the fissile layering typical of shale is developed. ... The term pelitic or pelite is often applied to these sediments and rocks.Streams eroded the softer rock in the mountains, lowering their height and carving new valleys. Outcrops of harder rock were left behind. Quartzite is what the rock you are looking at is mainly composed of.
The light grey or pinkish rock inclusions is called a Chert Band and is found in Quartzite. This type of rock was formed on the floor of an ancient ocean and is made up of the skeletons of microscopic marine animals called Radiolaria. It was squeezed into the hardening Quartzite as a vien or band then hardened along with the Quartzite.
The Questions.....
1. How did this rock end up on top of a mountain after being made in the ocean?
2. Look at the rock at GZ, Can you see any light grey or pinkish rock? What is this inclusion called and how was it made?
3. What is the name of the mountain range in the distance (to the west)?
4. What type of rock is the feature rock?
As this is an Earthcache you are required to send the answers to the cache owner prior to logging as found, you don’t have to wait for permission and the CO will let you know of any problems.
Feel free to add a photo but please make sure the relevant info on the signs is left out.
Information courtesy of NPSR QLD.