You are allowed to alight from your vehicle here BUT remember that you are in the Kruger park and that wild animals do roam freely here. Please make sure it is safe BEFORE getting out of your car.
There is an entrance fee to enter the Kruger National Park. Wild Card holders can get in for free.
While on holiday we stopped at this site and I immediatly knew what weathering process had taken place here so decided to make it into and Earth Cache. To complete this Earth cache you will need to park and take a walk to the boulder with the plaque.
A geological map of the Kruger shows that the main rock types are organised into broad bands, oriented in an approximately north-south direction. The park can therefore be basically divided into the older granitic rocks (estimated to be between 3.5 – 2.5 billion years old) on the western side of the reserve and the basaltic rocks (estimated to be around 250 million years old) on the east.
Granite domes orginate from Batholiths and Laccoliths.
A Batholith is a large dome shaped intrusion of magma which occurs at great depths beneath the earths surface. The magma cools slowly to form large masses of rock usually granite with no bedding plates.
Laccoliths are smaller mushroom shaped intusions of magma connected by a pipe to the source from where the magma intruded. Magma intruding between the layers of rock causes the overlying sedimentary rock strata to dome upwards. If they cool deep in the crust they are composed of granite.
The weight of the rocks and weathered material lying above the granite rock compresses it. Erosion of the surface material eases the pressure on the rock which causes curved pressure release joints to develop. The erosion eventually cause the dome to become exposed.
Joints formed when the magma cooled, contracted and solidified to form granite are called contractual joints and cross one another at right angles.
Due to the existance of the curved pressure release joints exfoliation type weathering causes sheets to peel of the granite mass. Exfoliation weathering is caused by the outer layer of rock expanding and contracting as it is heated during the day and cooled at night. These out layerrs eventually flake off from the main rock/dome.
Claiming the find:
- Standing directly in front of the tablets, at your feet, is a piece of rock that has flaked off due to exfoliation. Estimate the width, length and depth of depth of this piece.
- Are there any contractual or pressure release joints present?
- What type of weathering is exfoliation?
- On the plaque are two dates, what are they?
- Please post an optional picture of yourself at the GZ with the Tablets in the background.