The Darling Fault
The Darling Fault is one of the major fractures in the Earth's crust. At over 1000km long it can be seen from space! The Darling Scarp forms the western edge of the Darling Plateau and separates it from the Swan Coastal Plain. At the foot of the scarp, on the gently sloping Ridge Hill Shelf, deposits caused by erosion along the scarp can be found. Somewhere beneath this is the actual Darling Fault.
The Lesmurdie Falls are at the western edge of the Darling Plateau. Here is where you can find numerous rock types such as granite and dolerite. Many years of erosion and geological forces have made what you can see today. A dyke is usually caused by magma forcing its way up through cracks in the existing rock, causing veins of different rock and of varying widths.
The rocks seen around the Falls are of two distinct types. The lighter-coloured and more abundant rock is granodiorite (similar to granite). The darker-coloured rock is dolerite which forms almost vertical bodies known as dykes exposed as broad lines across the land surface.
Please email me the answers to the following questions:
1. After reading the information in the description, what geological feature can account for the Lesmurdie Falls? And how has the escarpment resulted in the Falls formation?
2. At waypoint 1 (Dolerite) just before the viewing platform on the South side of the path, you'll find an excellent example of a Dolerite Dyke. How does this differ from the Granite it is surrounded by? Study the colour, texture and grain size.
3. At waypoint 2 (Pool) you'll find a small rockpool just about the Falls. The rocks around the creek are smoother than those closer to the path. What do you think has caused this?
4. Take a photo of yourself of the view to add to your found log.
What to do now:
In accordance with the guidelines, the procedure for logging an Earthcache is:
- Send me the answers.
- Log your visit. "People do not need to wait for permission to log your EarthCache."
Please note: If answers have not been received within 10 days, you will risk having your found log removed.