General:
The waypoint will lead you to geological feature point number G14. This waypoint is inside a fenced off area and you are allowed to exit your vehicle at this location. Please make sure that it is safe to do so. This is not a zoo. There are wild and dangerous animals in this area and for them you are just another food source so please be careful. If you walk pass trees please make sure there is nothing inside the trees. If you are bitten by a full grown Black Mamba you will have enough time left for a quick prayer.
History:
Pilansberg National park was originally owned by 3 local tribes. When Bophuthatswana became an independent homeland this park was proclaimed by the then local black government. About 52 farmers were bought out and moved. The little town called Pilansberg was flattened and today the old Magistrate court which serves as a restaurant remained. There is also a graveyard but it is only visible when proper controlled burning is done. The name Pilansberg will never be changed as this name belongs to Chief Pilane who owns vast land outside the park. Pilane's father fought against the Burghers with the British during the Anglo Boer wars. In return he received land for his service. The current size of this reserve has been increased from 55 250 ha to 57 250 ha in May 2004. There are plans in place to join Madikwe and Pilansberg in the future.
Geological background:
If a head count of more than 6000 animals are not enough for you than this park also offers some amazing geological formations. This is one of the few areas that offer you information boards with samples of the various rocks as found at this location. In Pilansberg a very rare formation called "Ring Dyke Complex" can be found.
The area today appears as if it is part of an extinct volcano. But this is not 100% correct and exact. Most of the magna cooled under the ground. Later the centre collapsed on itself forming the centre of the volcano. Today this centre can be found at Mankwe dam. About 300 million years ago there was some volcanic action to the side of Mankwe dam in the direction of the Pilansberg Information Centre. I found a reference that mentioned that this volcano was once about 7000 meters tall. This is higher than Mount Kilimanjaro in Kenya. Today it is only 700 meters high. (visit link)
During the millions of the years that followed after the collapse of the centre erosion have set in and the softer layers were removed and only the hard rock remained in the form of concentric circles. On this planet there are only three places this type of geological formation can be seen. Pilansberg is the best preserved.
Some very rare minerals and rocks can be found in this area such as Volcanic Tuff, Uranium-bearing Tuff, White Foyite, Green Foyaite, Red Foyaite, Green Foyaite, and Ledig Foyaite.
For detailed back ground information please visit the following interesting earth caches in this area.
(visit link)
(visit link)
White Foyaite
One can classify rocks as follows.
1. Igneous Rocks. This is formed by crystallization from magma.
2. Sedimentary rocks. This type of rocks is formed by the settling of mineral fragments from suspension in air or in water and or precipitation from solutions.
3. Metamorphic rocks. This is as a result of re-crystallization of the above types by the influence of an increasing pressure and temperature.
The rocks we find in this area are of igneous origin and they were formed by three processes.
1. Formed at the surface of the earth caused by explosive eruption of magma, rock fragments and gasses.
2. At the surface as a result of magma flows and which crystallized quickly.
3. Magma that was crystallizes below the surface of the earth which is called intrusive igneous rocks.
The foyaites found in the Pilanesberg have different names due to their different mineral compositions. Four varieties of foyaite are identified in Pilansberg and are called White Foyaite, Red Foyaite, Green Foyaite and Ledig Foyaite. At this location you will find an information board with a sample of a polished rock that represents the White Foyaite group. The polished rock has a granite appearance but never less this type of rock contains zero or very small amounts of quartz. The grain of this rock varies mostly between 1 and 6 mm.
You will notice that the White Foyaite is a coarse grain rock. This rock appears in the two prominent ring mountains. The rocks at this location and the hills in this area contain this type of rock.
This rock consists mainly of orthoclase which is a member of the potassium feldspar series and secondly it also contains nepheline which is a member of the feldspathoid group of minerals. If you observe the rocks in this area you will notice small pits on the surface of the rock and this is where the nepheline grains are washed out and it gives the rock a weathered texture. The white foyaite also contains specs of a light pinkish/purple mineral called eudialyte which is a zirconiumbearing mineral.
Questions:
There is no phsical container - to log the cache you need to do the following.
- At this location a polished sample can be observed with some information. Please study this rock. Describe the texture, grain and colours that can be seen. Please do not publish this on the listing. Use a magnifying glass for a better view.
- Would you classify white Foyaite in this location as an Igneous rock or Sedimentary rock or as Metamorphic rock? Please justify your answer.
- Take a picture of you/group and publish it on the listing. Make sure that you have this type of rock in the background- not the sample. If needed you can sit down and put your head against the rock. Ok, please check the area for any nasties before this attempt or if any rock is lifted. If it is small then you can hold it while balancing on one leg. Sorry I got carried away - no one leg stance required. If it is big make sure that it does not crush you. Publish the photo on the listing. (This is an optional request and not a requirement to log).
References:
FTF Honours:
- Platinum: Hemachatus (First EC found by him, well done).
- Gold: BjBez
- Silver: Cincol and cslyoda
- Bronze: Carbon Hunter
Risk and Hazards (1 is low, 3 is average, 5 is extreme):
- Scorpions - 4 (Under rocks and poisonous)
- Heights and falls: 2
- Lightening - 4 (Highest Point)
- Slipping - 3
- Strong winds - 3
- Wet weather - 3
- Snakes - 4
- Spiders - 4
- Muggles and muggers- 2
- Night Time - XX (Not allowed)
- Roads - 3
- Children - 3 (Keep an eye on them)
- Thorns & Blackjacks - 2
- Other wild animals - 4
- Cacher - 1 (Suitable for the newbie to advanced cacher, no special skills needed)
Incidents at this cache:
- None recorded.
The rate of cooling and the makeup of the magma affected the type of rock that formed in each dike. For instance, white foyaite has particularly coarse grains and is formed when lava cools slowly. Red syenite forms when magma contains plenty of water. In the detail image, outcrops of white and green foyaite and of red syenite make up the ridges in the southwestern part of the park
